Mr
Atsuo Iiyoshi
(Chubu University, 1200 Matsumoto, Kasugai, Aichi, 487-8501 Japan)
17/10/2016, 09:00
It has been more than half a century since fusion energy research was disclosed at the 2nd Atoms for Peace conference, held in September, 1958 in Geneva. During the course of this period, DT-burning experiments were actually conducted in TFTR and in JET, both intended for energy breakeven: Q=1. This is a tremendous achievement of mankind, wishing to create a self-burning star on the Earth....
Mr
Florentino Portero
(Foundation Isaac Albéniz)
17/10/2016, 09:30
Human beings have a short history in universe terms. Just 200.000 years old and no more than 100.000 years old out of Africa. As a consequence of climate changes those men decided to leave the continent looking for new land and new opportunities to prosper. It is impossible to understand the history of the humankind without keeping in mind its effort to understand the reality and to overcome...
Yasuhiko Takeiri
(National Institute for Fusion Science)
17/10/2016, 10:45
Yasuhiko Takeiri for LHD Experiment Group
The final goal of the LHD project is to obtain the high performance helical plasma relevant to the fusion reactor, i.e., ion and electron temperature T_i > 10 keV, volume averaged beta > 5 %, fusion triple product n_e tau_E Ti > 1020 keV m^-3 s, and long pulse length of more than 3600 s with heating power of 3 MW. In order to achieve this...
Prof.
Bernard Bigot
(ITERFr)
17/10/2016, 11:10
The ITER project is a critical step in the development of fusion energy: its role is to confirm the feasibility of exploiting magnetic confinement fusion for the production of energy for peaceful purposes by providing an integrated demonstration of the physics and technology required for a fusion power plant. Rapid progress is being made in the design, manufacturing, construction and R&D...
Dr
Wayne M. Solomon
(General Atomics)
17/10/2016, 11:35
The DIII-D tokamak has addressed key issues to advance the physics basis for burning plasmas for ITER and future steady-state fusion devices. Developments on ITER scenarios include the discovery of a new wide-pedestal variant of QH-mode where increased edge transport is found to allow higher pedestal pressure, consistent with peeling-ballooning theory, and complete ELM suppression in...
Dr
xavier Litaudon
(EUROfusion)
17/10/2016, 12:00
The JET contributors
Europe has elaborated a Roadmap to the realisation of fusion energy in which ‘ITER is the key facility and its success is the most important overarching objective of the programme’. We review the contribution of the recent JET experiments with the ITER first wall materials mix, and, the underlying physics understanding to mitigate the scientific risks identified in the...
Prof.
Francisco Castejón
(CIEMAT)
17/10/2016, 14:00
Recent improvements in diagnostics and operation have led to better understanding of 3-D effects on transport and plasma control in the TJ-II stellarator. Impurity transport: Direct measurments of electrostatic potential variations within the same magnetic flux surface in ECRH plasmas are presented. Calculations show that such asymmetries affect impurity accumulation. The asymmetry value and...
Prof.
Hiroshi AZECHI
(Institute of Laser Engineering, Osaka University)
17/10/2016, 14:00
Here we report recent progress of the fast ignition inertial confinement fusion demonstration. Fraction of low energy (< 1 MeV) component of the relativistic electron beam (REB), which efficiently heats the fuel core, increases by the factor of 4 by enhancing pulse contrast of heating laser and removing preformed plasma sources. Kilo-tesla magnetic field is studied to guide the diverging REB...
Dr
Wayne M. Solomon
(Princeton Plasma Physics Laboratory)
17/10/2016, 14:00
The DIII-D tokamak has addressed key issues to advance the physics basis for burning plasmas for ITER and future steady-state fusion devices. Developments on ITER scenarios include the discovery of a new wide-pedestal variant of QH-mode where increased edge transport is found to allow higher pedestal pressure, consistent with peeling-ballooning theory, and complete ELM suppression in...
Prof.
Sergei Krasheninnikov
(University California San Diego)
17/10/2016, 14:00
The processes involving edge plasma and plasma-material interactions in magnetic fusion devices are very multifaceted and include a wide spectrum of phenomena ranging from plasma turbulence and meso-scale stability, recycling and transport processes of hydrogen species in the wall material, to the modification of wall material properties. In many cases these processes are strongly coupled and...
Yasuhiko Takeiri
(National Institute for Fusion Science)
17/10/2016, 14:00
The final goal of the LHD project is to obtain the high performance helical plasma relevant to the fusion reactor, i.e., ion and electron temperature T_i > 10 keV, volume averaged beta > 5 %, fusion triple product n_e tau_E Ti > 1020 keV m^-3 s, and long pulse length of more than 3600 s with heating power of 3 MW. In order to achieve this objective, the deuterium plasma is expected to have...
Prof.
Robert Wolf
(Max-Planck-Institute for Plasma Physics)
17/10/2016, 14:00
The main objective of the optimized stellarator Wendelstein 7-X (W7-X) is the demonstration of steady-state plasma operation at fusion relevant plasma parameters thereby verifying that the stellarator is a viable fusion power plant concept. The design of W7-X is based on an elaborate optimization procedure to overcome the shortcomings of the concept. After completing the main construction...
Prof.
Raymond Fonck
(University of Wisconsin-Madison)
17/10/2016, 14:00
Studies at near-unity aspect ratio offer unique insights into the high confinement (H-mode) regime and support development of novel startup scenarios. Ohmic H-mode operation has been attained at A < 1.3. Edge plasma parameters permit probe measurements of the edge pedestal, including the local current density profile, with high spatial and temporal resolution. H-mode plasmas have standard L-H...
Prof.
Kimitaka Itoh
(NIFS)
17/10/2016, 14:00
This article assesses the understanding of and impacts by the hysteresis of transport relation. The rapid changes of fluxes compared to slow changes of plasma parameters are overviewed for both edge barrier and core plasmas. The theoretical approaches to understand the direct influence of heating power on turbulent transport are addressed. The advanced data analysis method to search the...
Mr
Paul Wouters
(Fusion For Energy)
17/10/2016, 14:00
The ITER project is being undertaken at Cadarache, France, to construct and operate an experimental nuclear fusion facility. The aim of this paper is the description of the implementation of the French Order of February 7, 2012, concerning Nuclear Installation (called Installation Nuclear de Base, INB) in France within the European Domestic Agency (EU-DA). For protection of Public Safety,...
Prof.
Boris Breizman
(The University of Texas at Austin)
17/10/2016, 14:00
This overview talk covers recent developments in the theory of runaway electrons in tokamaks. Such electrons are known to be of serious concern with regard to safe operation of large-scale tokamaks in general and ITER in particular. They can quickly replace a large part of the bulk electron current during disruptions, and the corresponding magnetic energy exceeds the particle kinetic energy....
Dr
Arne Kallenbach
(Max-Planck-Institut f. Plasmaphysik)
17/10/2016, 14:00
The ASDEX Upgrade program is devoted to the preparation of ITER operation and the development of plasma scenarios and physics understanding for a future DEMO. Different scenario lines adapted to critical research tasks are developed and naturally integrated with the metallic, high-Z plasma facing components environment. The scenarios can be mainly divided into low core collisionality and high...
Dr
Arne Kallenbach
(Max-Planck-Institut f. Plasmaphysik)
17/10/2016, 14:00
The ASDEX Upgrade program is devoted to the preparation of ITER operation and the development of plasma scenarios and physics understanding for a future DEMO. Different scenario lines adapted to critical research tasks are developed and naturally integrated with the metallic, high-Z plasma facing components environment. The scenarios can be mainly divided into low core collisionality and high...
Prof.
Yican Wu
(Institute of Nuclear Energy Safety Technology (INEST),Chinese Academy of Sciences)
17/10/2016, 14:00
A fusion DEMO reactor, like other advanced nuclear energy systems, must satisfy several goals including a high level of public and worker safety, low environmental impact, high reactor availability, a closed fuel cycle, and the potential to be economically competitive. The experience of the ITER project will facilitate DEMO programs in developing a safety approach and a safety design,...
Dr
Baonian Wan
(Institute of Plasma Physics, Chinese Academy of Sciences)
17/10/2016, 14:00
EAST aims to demonstrate steady-state advanced high-performance H-mode plasmas with ITER-like configuration, plasma control and heating schemes. Since 2015, EAST has been equipped with all ITER-related auxiliary heating and current drive systems. Two NBI systems injected from Co- and Ctr-current directions, have been installed on EAST and allow the flexible study of the plasma rotation effect....
Dr
Jonathan Menard
(Princeton Plasma Physics Laboratory)
17/10/2016, 14:00
The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and NSTX Upgrade (NSTX-U) is now the most capable Spherical Torus/Tokamak (ST) in the world program. NSTX-U mission elements include: exploring unique ST parameter regimes to advance predictive capability for ITER and beyond, developing solutions for the plasma-material interface challenge, and advancing the ST as a...
Dr
Earl Marmar
(Mass. Inst. of Technology)
17/10/2016, 14:00
C-Mod is the only divertor tokamak in the world capable of operating at B fields up to 8 T, equaling and exceeding that planned for ITER. C-Mod is compact, thus accessing regimes of extreme edge power density (1 MW/m2 average through the plasma surface). Scrape-off layer (SOL) power widths are of order of a few mm, with measured parallel power flows >1 GW/m2 at the divertor, surpassing the...
Prof.
John Sarff
(University of Wisconsin-Madison)
17/10/2016, 14:00
The reversed field pinch (RFP) offers unique capabilities that could be essential to closing gaps to fusion power. The RFP has large plasma current and small toroidal field, with q(r)<1. Two key benefits arise: (1) the possibility for ohmic heating to ignition and (2) minimization of the field strength at the magnets. The material boundary can be made invisible to an inductive electric field,...
Dr
Renaud Dejarnac
(CzIPP)
17/10/2016, 14:00
The COMPASS tokamak is one of the present devices operating with an ITER-like plasma shape. Its flexibility combined to an extensive set of diagnostics and NBI heating allow to address a broad range of key areas in support of the worldwide fusion programme such as H-mode, MHD, RAE, disruptions, PWI. The recent results obtained in COMPASS addressing these key issues are reviewed here.
The...
Mr
Rakesh Tanna
(Institute For Plasma Research)
17/10/2016, 14:00
Several experiments, related to controlled thermonuclear fusion research and highly relevant for large size tokamaks including ITER, have been carried out in ADITYA, an ohmically heated circular limiter tokamak. Repeatable plasma discharges of maximum plasma current of ~ 160 kA and discharge duration beyond ~ 250 ms with plasma current flattop duration of ~ 140 ms has been obtained for the...
Prof.
Xuru Duan
(Southwestern Institute of Physics)
17/10/2016, 14:00
Recent experiments on the HL-2A tokamak have been aimed at the major challenges relevant to ITER operation and fusion energy development. Significant progress has been achieved in many areas, including the first demonstration of high coupling efficiency of LHCD passive-active multi-junction (PAM) antenna in H-mode discharges, pedestal instability and dynamics, ITB formation mechanism,...
Dr
Andrew Kirk
(Culham Centre for Fusion Energy)
17/10/2016, 14:00
New results from MAST will be presented that focus on validating models in order to extrapolate to future devices. Particular attention will be given to the areas of scenario development, fast particle physics and plasma exhaust. Understanding filamentary transport across the scrape off layer is a key issue for the design and operation of future devices as it is crucial in determining the...
Dr
Duarte Borba
(EUROfusion Programme Management Unit, Culham Science Center, Abingdon, UK)
17/10/2016, 14:00
Following the successful operation of a European High Performance Computer For Fusion applications (HPC-FF) in Jülich, Germany, from 2009 to 2013, a new supercomputer dedicated to magnetic fusion research was procured within the Broader Approach agreement between Europe and Japan. The new platform, “Helios”, was installed in the International Fusion Energy Research Centre - Computational...
Prof.
Yuichi Takase
(University of Tokyo)
17/10/2016, 14:00
Nationally coordinated research on spherical tokamak (ST) is being conducted in Japan, to strengthen the scientific basis and to broaden future options of ST applications. The research themes to concentrate on are (1) the physics of very high beta plasmas, (2) development of start-up, current drive, and control techniques without the use of the central solenoid (CS), and (3) demonstration of...
Dr
Subrata Pradhan
(Institute for Plasma Research)
17/10/2016, 14:00
Steady State Superconducting Tokamak (SST-1) is a `operational’ experimental superconducting device since late 2013. Since last IAEA-FEC; SST-1 has been upgraded with Plasma Facing Components being installed and integrated in the vacuum vessel and is getting prepared towards long pulse operations in both circular and elongated configurations. The PFC integration has been completed in August...
Dr
Gianluca Pucella
(ENEA)
17/10/2016, 14:00
Experiments of Electron Cyclotron (EC) assisted breakdown have shown the presence of runaway electrons (RE) also below the Dreicer electric field threshold, indicating that the RF power acts as seeding for fast electrons, and a large database of post-disruption generated RE beams has been analysed in order to identify linear dynamical models for new position and current RE beam controllers. A...
Dr
juan knaster
(IFMIF/EVEDA)
17/10/2016, 14:00
IFMIF, the International Fusion Materials Irradiation Facility, presently in its Engineering Validation and Engineering Design Activities (EVEDA) phase under the Broader Approach Agreement, will allow accelerated testing of structural materials with fusion relevant neutrons at >20dpa/year in 500cm3. IFMIF consists of two 125 mA and 40 MeV D+ linear accelerators operating in CW mode. The...
Dr
xavier Litaudon
(EUROfusion)
17/10/2016, 14:00
The JET contributors
Europe has elaborated a Roadmap to the realisation of fusion energy in which ‘ITER is the key facility and its success is the most important overarching objective of the programme’. We review the contribution of the recent JET experiments with the ITER first wall materials mix, and, the underlying physics understanding to mitigate the scientific risks identified in the...
Dr
Yeong-Kook Oh
(National Fusion Research Institute)
17/10/2016, 14:00
The KSTAR device has been operated since the first plasma in 2008 with the mission of exploring the physics and technologies of high performance steady-state operation that are essential for ITER and fusion reactor. KSTAR has been focusing on maximizing performance and extending pulse length targeting H-mode dischage up to 300s at higher plasma current up to 2 MA, and at higher normalized beta...
Prof.
Yuanxi WAN
(Institute of Plasama Physics, Chinese Academy of Sciences)
17/10/2016, 14:00
The Chinese Fusion Engineering Testing Reactor (CFETR) is the next device for the Chinese magnetic confinement fusion (MCF) program which aims to bridge the gaps between the fusion experiment ITER and the demonstration reactor DEMO. CFETR will be operated in two phases: Steady-state operation and tritium self-sustainment will be the two key issues for the first phase with a modest fusion power...
Dr
Matteo Zuin
(Consorzio RFX, Padova, Italy)
17/10/2016, 14:00
Thanks to its flexibility and unique control capability, the RFX-mod device has been operated in the last two years to investigate a wide range of experimental conditions. Reversed-Field Pinch (RFP), Tokamak and the full range of magnetic configurations in between the two, the ultra-low q, have been produced to contribute to physics common topics highlighting similarities and/or peculiarities....
Dr
Stefano Coda
(CRPP-EPFL)
17/10/2016, 14:00
A broad upgrade program is underway at the TCV tokamak. A historic first step is the present commissioning of the first neutral beam injector (NBI), delivering 1 MW of power at energies in the 15-30 keV range. Four gyrotrons are also being added in 2016-2018 to bring the total ECRH power to 6 MW. A second, counter-injected, 1-MW neutral beam is also planned, in addition to the introduction of...
Mr
Ge Zhuang
(Huazhong University of Science and Technology)
17/10/2016, 14:00
The progress of experimental research over last two years on the J-TEXT tokamak is reviewed, the most significant results including: the investigation of the effect of resonant magnetic perturbations (RMPs) on the J-TEXT operation region, impurity transport and confinement, and runaway electrons suppression; study of the threshold for runaway current generation; and identification of the...
Dr
Hiroshi SHIRAI
(Japan Atomic Energy Agency)
17/10/2016, 14:00
The JT-60SA project has been promoted since June 2007 under the framework of the Broader Approach (BA) agreement and Japanese national fusion programme for an early realization of fusion energy by conducting supportive and complementary work for the ITER project and directing DEMO design activity. With the powerful and varied deposition profile of heating and current drive system, flexible...
Mr
Dmitrii Sarychev
(NRC "Kurchatov Institute")
17/10/2016, 14:00
Review of the recent experimental results obtained on the T-10 tokamak is presented. To decrease the level of light impurities in 2015 both the rail and circular limiters were replaced with ones made of tungsten. The used tungsten type «POLEMA» as well as the technology of its soldering to the bronze substrate are similar to those applied for the production of the ITER divertor tiles. In the...
Dr
Michael John Edwards
(Lawrence Livermore National Laboratory)
17/10/2016, 14:00
M. J. Edwards1, T. C. Sangster2, D. B. Sinars3 1 Lawrence Livermore National Laboratory, Livermore, CA 94551, USA 2 Laboratory for Laser Energetics, 250 E. River Rd, Rochester, NY 14623-1299, USA 3 Sandia National Laboratories, Albuquerque, NM 87185, USA
Ignition and significant fusion yield from Inertial Confinement Fusion (ICF) remains a grand scientific challenge. The ICF community in the...
Prof.
Yunfeng Liang
(Forschungszentrum Jülich GmbH, Germany)
17/10/2016, 14:25
EAST aims to demonstrate steady-state advanced high-performance H-mode plasmas with ITER-like configuration, plasma control and heating schemes. Since 2015, EAST has been equipped with all ITER-related auxiliary heating and current drive systems. Two NBI systems injected from Co- and Ctr-current directions, have been installed on EAST and allow the flexible study of the plasma rotation effect....
Dr
Boris Breizman
(Institute for Fusion Studies, The University of Texas, Austin, Texas, 78712 USA)
17/10/2016, 14:50
This overview talk covers recent developments in the theory of runaway electrons in tokamaks. Such electrons are known to be of serious concern with regard to safe operation of large-scale tokamaks in general and ITER in particular. They can quickly replace a large part of the bulk electron current during disruptions, and the corresponding magnetic energy exceeds the particle kinetic energy....
Dr
Yeong-Kook Oh
(National Fusion Research Institute)
17/10/2016, 15:15
The KSTAR device has been operated since the first plasma in 2008 with the mission of exploring the physics and technologies of high performance steady-state operation that are essential for ITER and fusion reactor. KSTAR has been focusing on maximizing performance and extending pulse length targeting H-mode dischage up to 300s at higher plasma current up to 2 MA, and at higher normalized beta...
Dr
Earl Marmar
(Mass. Inst. of Technology)
17/10/2016, 15:40
C-Mod is the only divertor tokamak in the world capable of operating at B fields up to 8 T, equaling and exceeding that planned for ITER. C-Mod is compact, thus accessing regimes of extreme edge power density (1 MW/m2 average through the plasma surface). Scrape-off layer (SOL) power widths are of order of a few mm, with measured parallel power flows >1 GW/m2 at the divertor, surpassing the...
Prof.
Peng FU
(Institute of Plasma Physics, Chinese Academy of Sciences)
17/10/2016, 16:40
ASIPP has taken the responsibility of most CN ITER package. All packages follow current ITER schedule.
The superconducting conductor package consists of 106 conductors with 6 kinds includes 7.5% TF conductor,totalPF conductor from PF2 to PF5, total CC conductor, and MB and CB conductor of feeder. Now total CN TF conductor package has been completed in production,and delivered to IO; completed...
Mr
John Smith
(General Atomics)
17/10/2016, 17:00
The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER.
The...
Dr
JUNICHI HIRATSUKA
(National Institutes for Quantum and Radiological Science and Technology)
17/10/2016, 17:20
A. In order to realize the negative-ion-based neutral beam (NB) systems for ITER and JT-60SA, development of the Multi-Aperture and Multi-Grid (MAMuG) electrostatic accelerator is one of common critical issues. For these NB injectors, 5- and 3-stage MAMuG accelerators are being developed to achieve the acceleration of negative ion beams up to 1 MeV, 40 A (200 A/m^2) for 3600 s and 0.5 MeV, 22...
Dr
Masashi Kisaki
(JpNIFS)
17/10/2016, 17:40
Development of the high performance negative hydrogen ion source is a fundamental demand in realizing fusion reactor. In order to clarify the extraction mechanism of H^-, temporal and spatial variations of the negative ions and electrons in the extraction region are intensively surveyed at NIFS. In addition, the beam acceleration experiments have been performed by changing the accelerator...
Mrs
Aparajita Mukherjee
(Institute for Plasma Research, India)
17/10/2016, 18:00
The IC H&CD system is one of the major tools for achieving the plasma performances foreseen in ITER's operation scenario. This system is designed to provide 20 MW into the plasma, at frequencies included in the band 40 MHz to 55 MHz. For ensuring 20 MW power availability for plasma operation, 24 MW is required at the output of the RF sources. India is responsible to deliver nine numbers of RF...
Prof.
Grigory Denisov
(Institute of Applied Physics Ruissian Academy of Sciences)
17/10/2016, 18:20
A. Gyrotrons for plasma fusion installations usually operate at frequencies 40-170 GHz. Requested output power of the tubes is about 1 MW and pulse duration is between seconds and thousands seconds. To provide operation with indicated parameters the gyrotrons have very large transverse cavity sizes, output barrier windows made of CVD diamond discs, effective collectors with particle energy...
Dr
Shizuo Inoue
(Japan Atomic Energy Agency)
18/10/2016, 08:30
We report a numerical study of a mode locking in tokamaks, which reveals an active stabilization effect of the control field against the locking event. We developed the resistive MHD simulation code “AEOLUS-IT”, which can simulate mode locking, where the magnetic island interacts with error/control field, under JT-60SA class high magnetic Reynolds number condition. The developed code...
Dr
Victor Lukash
(National Research Centre «Kurchatov Institute», Pl. Kurchatova 1, Moscow 123182, Russia)
18/10/2016, 08:30
Disruption mitigation with use of the massive injection of noble gases (MGI) is widely used and experimentally validated on contemporary tokamaks. The disruption mitigation system (DMS) in ITER is aiming to subsequently or simultaneously achieve a solution for 3 main goals including mitigation of the heat loads on the plasma facing components during thermal quenches (TQs), keeping tolerable...
Dr
Jungpyo Lee
(MIT Plasma Science and Fusion Center, USA)
18/10/2016, 08:30
In this study, the maximum achievable elongation in a tokamak against the n=0 MHD resistive wall mode is investigated theoretically and compared with experimental observations. A highly elongated plasma is desirable to increase plasma pressure and confinement for high fusion power output. However, there is a limit on the maximum achievable elongation which is set by vertical instabilities...
Dylan Brennan
(Princeton Plasma Physics Laboratory)
18/10/2016, 08:30
Well before ITER operations begin, we must have a comprehensive understanding of the potential for runaway electron generation, as well as methods for their control and mitigation, as the destructive potential to the plasma facing components is severely intolerable. This makes for a unique situation in requiring an assessment based on plasma theory and computation well before validation...
Dr
Jose Ramon Martin-Solis
(Universidad Carlos III de Madrid)
18/10/2016, 08:30
Runaway electrons (REs) generated during disruptions are usually found to deposit their energy in very short pulses and on localized areas of the plasma facing components (PFCs). In ITER, there is serious concern about the potential that large amounts of MeV REs generated during the disruption current quench (CQ) have for erosion / melting of the PFCs. Although zero-dimensional (0-D) modeling...
Dr
Ryosuke Ikeda
(Japan Atomic Energy Agency)
18/10/2016, 08:30
Mega-watt gyrotrons with frequency tuning have become essential devices in fusion science to perform effective EC H&CD. JAEA is developing two types of multi-frequency gyrotrons equipped with a triode magnetron injection gun for ITER and JT-60SA. A TE31,11 mode, which is a candidate mode for 170 GHz oscillation, has sufficient margin for cavity heat-load in 1 MW operation, and it has a great...
Dr
Tsuyoshi Kariya
(Plasma Research Center, University of Tsukuba)
18/10/2016, 08:30
Megawatt (MW) gyrotrons with a wide frequency range from 14 to 300 GHz are being developed for the collaborative Electron Cyclotron Heating (ECH) study of advanced fusion devices and DEMO reactor. (1) In the first experiment of 300 GHz gyrotron, an output power of over 0.5 MW with TE32,18 single-mode was achieved with a pulse width of 2 ms. This is the first report of MW level oscillation with...
Prof.
Volodymyr Mykhaylenko
(Pusan National University)
18/10/2016, 08:30
Numerous experimental observations from number of tokamaks and stellarators have found large nearly sonic magnetic field aligned (parallel) shear flows that are peaked at the last closed flux surfaces and extend for a few centimeters into the plasma and into the far SOL. The important consequence is that these plasma regions are unstable in the presence of shear flows. The shear flows along...
Dr
Remir Shurygin
(NRC ‘Kurchatov Institute’, Moscow, Russia)
18/10/2016, 08:30
Numerical calculations of nonlinear MHD equations in frames of reduced two-fluid Braginskij equations for geodesic acoustic modes (GAM) with n = 0, m = 0, +1, -1 in high collisional edge tokamak plasma were performed. N = 0, m = 0, +1, -1. It was shown that with account of parallel dissipation (finite conductivity sigma//) allows us to obtain the steady state equilibrium solutions for GAMs....
Prof.
Zhongtian Wang
(School of Science, Xihua University;Southwestern Institute of Physics)
18/10/2016, 08:30
An e-fishbone frequency jump has been observed on Tore Supra , which is important for the redistribution of energetic electrons and energetic particle losses. E-fishbone periodic frequency jump phenomena are also observed on HL-2A . Soft X-ray tomography shows that the poloidal and toroidal mode numbers are 1/1 and 2/2 with the frequency jump. In this paper we present a theoretical base of the...
Prof.
Masaru FURUKAWA
(Graduate School of Engineering, Tottori University)
18/10/2016, 08:30
The theory of matched asymptotic expansion for resistive MHD is well established for linear modes [1] and for weakly nonlinear evolution [2]. Since then many applications of the Rutherford equation [2] have made much progress in fusion research, especially in the neoclassical tearing mode (NTM) studies [3]. However, the theoretical framework is still based on the Rutherford equation...
Prof.
Robert Wolf
(Max-Planck-Institute for Plasma Physics)
18/10/2016, 08:30
The main objective of the optimized stellarator Wendelstein 7-X (W7-X) is the demonstration of steady-state plasma operation at fusion relevant plasma parameters thereby verifying that the stellarator is a viable fusion power plant concept. The design of W7-X is based on an elaborate optimization procedure to overcome the shortcomings of the concept. After completing the main construction...
Dr
Junya Shiraishi
(Japan Atomic Energy Agency)
18/10/2016, 08:30
We found that inclusion of self-consistent rotation effect in the energetic particles’ dynamics has significant impact on resistive wall mode (RWM) stability in tokamaks. For the first time, we apply the extended kinetic-magnetohydrodynamic (MHD) theory for rotating plasmas to energetic particles. The theory invokes an extended energy exchange term between the MHD mode and energetic particles’...
Mr
John Smith
(General Atomics)
18/10/2016, 08:30
The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER.
The...
Dr
JUNICHI HIRATSUKA
(Japan Atomic Energy Agency)
18/10/2016, 08:30
In order to realize the negative-ion-based neutral beam (NB) systems for ITER and JT-60SA, development of the Multi-Aperture and Multi-Grid (MAMuG) electrostatic accelerator is one of common critical issues. For these NB injectors, 5- and 3-stage MAMuG accelerators are being developed to achieve the acceleration of negative ion beams up to 1 MeV, 40 A (200 A/m^2) for 3600 s and 0.5 MeV, 22 A...
Dr
Nikolay Ivanov
(Kurchatov Institute)
18/10/2016, 08:30
The non-axisymmetric halo current arising due to loss of plasma vertical equilibrium, the so-called vertical displacement event (VDE), during plasma disruption in vertically elongated tokamak can be one of possible sources of helical magnetic perturbation. This perturbation penetrate into plasma producing magnetic islands in the vicinity of resonant magnetic surface with the same helicity....
Prof.
Bruno Coppi
(M.I.T.)
18/10/2016, 08:30
In the context of a two-fluid theory of magnetic reconnection [1], when the longitudinal electron thermal conductivity is relatively large, the perturbed electron temperature tends to become singular [2] in the presence of a reconnected field component and an electron temperature gradient. A transverse thermal diffusivity is introduced in order to remove this singularity while a finite...
Linjin Zheng
(University of Texas at Austin)
18/10/2016, 08:30
MHD stability of ITER H-mode confinement is investigated with bootstrap current included for equilibrium, together with diamagnetic drift and rotation effects for stability. The ITER pedestal has high temperature, so the bootstrap current is large and diamagnetic effects are important. We construct numerically ITER equilibria with bootstrap current taken into account.Especially, we have...
Dr
Alexandre Fil
(Princeton University)
18/10/2016, 08:30
In this paper we present high level simulations and modeling of pedestal control for NSTX-U. Real-time pedestal control is a crucial topic for future fusion reactors and ITER where pedestal has to be kept Edge-Localized-Modes (or ELMs) free. We developed and tested many different control schemes to adjust and regulate the pedestal at DIII-D and we plan to test them on NSTX-U. But to do this it...
Prof.
Grigory Denisov
(Institute of Applied Physics Russian Academy of Sciences)
18/10/2016, 08:30
Gyrotrons for plasma fusion installations usually operate at frequencies 40-170 GHz. Requested output power of the tubes is about 1 MW and pulse duration is between seconds and thousands seconds. To provide operation with indicated parameters the gyrotrons have very large transverse cavity sizes, output barrier windows made of CVD diamond discs, effective collectors with particle energy...
Dr
Marina Becoulet
(IRFM/CEA)
18/10/2016, 08:30
The non-linear MHD modelling of full ELM crash dynamics was performed using JOREK code for KSTAR pulse parameters and compared to the ECEI diagnostic observations. Some experimentally observed trends were reproduced in modelling. In particular the localization of the peeling-ballooning modes in the pedestal region inside the separatrix, the most unstable modes toroidal numbers and structures,...
Dr
Shimpei Futatani
(Barcelona Supercomputing Center)
18/10/2016, 08:30
ITER operation relies on the achievement of the H-mode confinement regime, which is expected to lead to the quasi-periodic triggering of ELMs (Edge Localized Modes). The energy fluxes associated with natural ELMs will produce excessive erosion and/or damage on the plasma facing component. Controlled triggering of ELMs by the injection of small pellets at frequencies exceeding those of natural...
Dr
Francois Orain
(Max Planck Institute for Plasma Physics, Garching, Germany)
18/10/2016, 08:30
One of the foreseen methods to control the Edge Localized Modes (ELMs) in ITER is the application of Resonant Magnetic Perturbations (RMPs), proved capable to mitigate or suppress ELMs in existing tokamaks. However the significant uncertainties that remain regarding the way plasma flows and ELMs interact with RMPs must be overcome to give reliable predictions for ITER. This work aims at...
Dr
Stephen jardin
(UsPPPL)
18/10/2016, 08:30
The goal of the present work is to better understand and develop a predictive capability for when approaching and crossing a MHD linear instability boundary leads to a thermal quench and subsequent disruption (hard limit), and when it just leads to increased transport or small amplitude oscillations (soft limit). Understanding the difference between hard and soft limits is crucial for...
Jacob King
(Tech-X Corporation)
18/10/2016, 08:30
It is desirable to have an ITER H-mode regime that is quiescent to edge-localized modes (ELMs). ELMs deposit large, localized and impulsive heat loads that can damage the divertor. A quiescent regime with edge harmonic oscillations (EHO) or broadband MHD activity is observed in some DIII-D, JET, JT-60U, and ASDEX-U discharge scenarios [Garofalo et al, PoP (2015); Burrell et al., PoP (2012);...
Dr
FENG LIU
(University of Nice)
18/10/2016, 08:30
Non-linear MHD simulations of DIII-D QH-mode plasmas have been performed with the non-linear MHD code JOREK as a first step towards determining whether the physics mechanisms leading to the QH-mode behaviour would be at work in ITER plasmas and thus whether this confinement regime can be considered as an alternative to the controlled Type I ELMy H-mode for ITER high Q operation. In the...
Prof.
Abhijit Sen
(Institute for Plasma Research)
18/10/2016, 08:30
We report on nonlinear simulation studies on the dynamical behaviour of ELMs under the influence of RMPs and/or the presence of pellet injection using a two-fluid
initial value electromagnetic nonlinear global code (CUTIE). The full set of model fluid equations are solved for the so-called mesoscale, an intermediate scale between
the device size and the ion gyroradius, incorporating...
Dr
Juhyung Kim
(National Fusion Research Institute)
18/10/2016, 08:30
We investigate the effect of resistivity, mainly on pitch resonant responses induced by plasma rotation. As a confirmation of the newly developed code, we report that the detailed physics may not be important since the pitch resonant response is relatively weak at high resistivity and the penetration is strongly dependent on plasma rotation at low resistivity. At low resistivity, ion...
Dr
Zhirui Wang
(Princeton Plasma Physics Laboratory)
18/10/2016, 08:30
Externally applied, nonaxisymmetric magnetic perturbations can strongly modify tokamak plasmas, leading to the plasma response. Plasma response, often closely related to the resonant field amplification and to the ELM control using magnetic coils, has been systematically observed in tokamak experiments. In particular, the importance of drift kinetic effects on modifying the plasma response has...
Dr
Vladimir Pustovitov
(National Research Centre “Kurchatov Institute”)
18/10/2016, 08:30
The paper is devoted to theoretical description of plasma stability in toroidal fusion systems with a resistive wall. Its aim is elimination of contradictions between different approaches and between theory and experiment. The study is related to two predictions stated as theorems, see [H. Tasso and G. N. Throumoulopoulos, Phys. Plasmas 18, 070702 (2011)] and references therein. One is that an...
Dr
ZHIBIN GUO
(University of California, San Diego)
18/10/2016, 08:30
We demonstrate E × B shear governs the dynamics of the cross phase of the peeling-ballooning-(PB)mode-driven heat flux, and so determines the evolution from the edge-localized (ELMy) H mode to the quiescent (Q) H mode. A physics-based scaling of the E × B shearing rate for accessing the QH mode is predicted. The ELMy H mode to the QH-mode evolution is shown to follow from the conversion from a...
Dr
Fatima Ebrahimi
(Princeton University/PPPL)
18/10/2016, 08:30
In a low-aspect-ratio Spherical Torus (ST), and in particular in an ST-based fusion reactor, due to the restricted space for a central solenoid, elimination of the central solenoid, and thus non-inductive current-drive techniques, is necessary. Transient Coaxial Helicity Injection (CHI) is a leading candidate for plasma start-up and current formation in NSTX-U. In NSTX, transient CHI has...
Dr
Indranil Bandyopadhyay
(ITER-India, Institute for Plasma Research)
18/10/2016, 08:30
Accurate modeling of major disruption (MD) and vertical displacement events (VDEs) in ITER is necessary to determine the halo current amplitude during these events and hence the electromagnetic loads on the machine components. The modeling of these events were originally done by DINA code and the results were later validated by TSC simulations and they both agree remarkably well when similar...
Dr
Joachim Geiger
(Max-Planck-Institute for Plasma Physics, Greifswald, Germany)
18/10/2016, 08:30
Wendelstein 7-X aims at quasi-steady-state operation to demonstrate the reactor-viability of stellarators optimized with respect to MHD-equilibrium and -stability, low neoclassical transport, small bootstrap current and good fast-particle confinement. To reach this goal an island divertor is foreseen for particle and energy exhaust, which utilizes the naturally occurring boundary islands...
Allan Reiman
(Princeton Plasma Physics Lab)
18/10/2016, 08:30
In toroidal MHD equilibria, pressure can generally be regarded as constant on the flux surfaces. The regions near small magnetic islands, and those near the X-lines of larger islands, are exceptions. We show that the variation of the pressure within the flux surfaces in those regions has significant consequences for the pressure driven current. We further show that the consequences are...
Mrs
Aparajita Mukherjee
(Institute for Plasma Research)
18/10/2016, 08:30
The IC H&CD system is one of the major tools for achieving the plasma performances foreseen in ITER's operation scenario. This system is designed to provide 20 MW into the plasma, at frequencies included in the band 40 MHz to 55 MHz. For ensuring 20 MW power availability for plasma operation, 24 MW is required at the output of the RF sources. India is responsible to deliver nine numbers of RF...
Dr
Masashi Kisaki
(National Institute for Fusion Science)
18/10/2016, 08:30
Development of the high performance negative hydrogen ion source is a fundamental demand in realizing fusion reactor. In order to clarify the extraction mechanism of H^-, temporal and spatial variations of the negative ions and electrons in the extraction region are intensively surveyed at NIFS. In addition, the beam acceleration experiments have been performed by changing the accelerator...
Prof.
Peng FU
(Institute of Plasma Physics, Chinese Academy of Sciences)
18/10/2016, 08:30
ASIPP has taken the responsibility of most CN ITER package. All packages follow current ITER schedule. The superconducting conductor package consists of 106 conductors with 6 kinds includes 7.5% TF conductor,totalPF conductor from PF2 to PF5, total CC conductor, and MB and CB conductor of feeder. Now total CN TF conductor package has been completed in production,and delivered to IO; completed...
Dr
Ahmet Aydemir
(National Fusion Research Institute, Daejeon, Korea)
18/10/2016, 08:30
Explosive growth of a ballooning finger is demonstrated in nonlinear magnetohydrodynamic calculations of high-beta disruptions in tokamaks. The explosive finger is formed by an ideally unstable n=1 mode, dominated by an m/n=2/1 component. The quadrupole geometry of the 2/1 perturbed pressure field provides a generic mechanism for the formation of the initial ballooning finger and its...
Tommaso BOLZONELLA
(ItRFX)
18/10/2016, 08:30
A careful numerical evaluation of MHD stability and of active control strategies is of paramount importance to reach one of the main goals of JT-60SA (Super Advanced) device, namely the development and qualification of high beta_N, steady-state regimes for future reactors like DEMO. Thanks to its powerful and flexible additional systems for heating and current drive, to its shaping...
Dr
Jong-Kyu Park
(Princeton Plasma Physics Laboratory)
18/10/2016, 08:30
Control of toroidal rotation is an important issue for tokamaks and ITER since the rotation and its shear can significantly modify plasma stability from microscopic to macroscopic scales. A potentially promising actuator for the rotation control is the non-axisymmetric (3D) magnetic perturbation, as it can substantially alter toroidal rotation by neoclassical toroidal viscosity (NTV). The...
Dr
Akinobu Matsuyama
(Japan Atomic Energy Agency)
18/10/2016, 08:30
Runaway electron (RE) generation after major disruptions is simulated over a full current quench (CQ) timescale, which covers both fast MHD events and slow RE avalanche amplification. A novel 3D RE analysis code EXTREM allows us to study (1) fast, global transport of REs with macroscopic MHD modes and (2) the RE generation triggered by electric fields induced owing to fast MHD dynamics (i.e.,...
Dr
Hideo Nuga
(Kyoto University)
18/10/2016, 08:30
The suppression and mitigation of runaway electron (RE) is an urgent issue of large scale tokamak operation. The contribution of hot-tail effect, which arises from the fast thermal quench, is studied using Fokker-Planck simulation. It is found that if the thermal quench is fast enough to invoke the hot-tail effect, it may produce seed REs and enhance total RE current even in a high electron...
Prof.
Katsuji ICHIGUCHI
(National Institute for Fusion Science)
18/10/2016, 08:30
Effects of the poloidal shear rotation on the magnetohydrodynamic (MHD) stability of interchange modes in a Large Helical Device (LHD) configuration are numerically studied. This simulation is the first three-dimensional (3D) full-MHD nonlinear analysis for heliotron plasmas including the flow.
In LHD, the highest average beta value of 5.1% is successfully obtained in the configuration where...
Dr
Emanuele Poli
(Max-Planck-Institute for Plasma Physics, Germany)
18/10/2016, 08:30
Our present understanding of the physics of the tearing mode (TM) still does not allow a quantitative prediction of TM evolution in fusion reactors. The early phase of a TM, in particular, is determined by a complex interplay of different processes. We investigate the physics of the TM via gyrokinetic (GK) simulations in toroidal geometry using the code GKW. Two routes are followed, namely...
254.
Towards powerful negative ion beams at the test facility ELISE for the ITER and DEMO NBI system
Prof.
Ursel Fantz
(Max-Planck-Institut fuer Plasmaphysik)
18/10/2016, 08:30
The negative ion source test facility ELISE represents an important step in the European R&D roadmap towards the neutral beam injection (NBI) systems at ITER. ELISE provides early experience with operation of large RF-driven negative hydrogen ion sources. Its source area is 1x0.9 m2 and the net extraction area of 0.1 m2, formed by 640 apertures, corresponds to a half-size ITER source. The test...
Dr
Hideaki Miura
(National Institute for Fusion Science)
18/10/2016, 08:30
Nonlinear growth of ballooning modes in a heliotron device is studied by means of two-fluid numerical simulations. A model to substitute an influence of the scales smaller than the grid size, Sub-Grid-Scale (SGS), on the scales larger than the Grid Scale (GS) is introduced. A simulation with the SGS model, a Large Eddy Simulation (LES), of two-fluid MHD model successfully shows growth of the...
Dr
Michael John Edwards
(Lawrence Livermore National Laboratory)
18/10/2016, 08:55
Ignition and significant fusion yield from Inertial Confinement Fusion (ICF) remains a grand scientific challenge. The ICF community in the US, together with international collaborators is executing a coordinated effort exploring 3 approaches to ignition each with different risks and advantages: laser driven x-ray drive, laser direct drive, and magnetic direct drive. This talk presents the...
Dr
Hiroshi SHIRAI
(Japan Atomic Energy Agency)
18/10/2016, 09:20
The JT-60SA project has been promoted since June 2007 under the framework of the Broader Approach (BA) agreement and Japanese national fusion programme for an early realization of fusion energy by conducting supportive and complementary work for the ITER project and directing DEMO design activity. With the powerful and varied deposition profile of heating and current drive system, flexible...
Prof.
Yuanxi WAN
(Institute of Plasama Physics, Chinese Academy of Sciences)
18/10/2016, 09:45
The Chinese Fusion Engineering Testing Reactor (CFETR) is the next device for the Chinese magnetic confinement fusion (MCF) program which aims to bridge the gaps between the fusion experiment ITER and the demonstration reactor DEMO. CFETR will be operated in two phases: Steady-state operation and tritium self-sustainment will be the two key issues for the first phase with a modest fusion power...
Paolo Piovesan
(Consorzio RFX)
18/10/2016, 10:45
This work investigates the formation of helical core equilibria in toroidal fusion plasmas, focusing on the role of dynamo, or magnetic flux pumping mechanisms in determining the equilibrium current profile. Dynamo effects determine the safety factor profile of the final 3D equilibrium, with important consequences on MHD stability and transport. We compare experimental results from multiple...
Dr
Carlos Paz-Soldan
(Oak Ridge Institute for Science Education)
18/10/2016, 11:05
Measurements and modeling of the plasma response to applied 3D magnetic perturbations – specifically its dependence on collisionality, beta, and rotation – yield new insight into the physics of edge-localized mode (ELM) control and better define the criteria needed to achieve ELM suppression in ITER. ELM control depends on the coupling of the applied field to a stable edge mode that drives...
Dr
Stuart Hudson
(Princeton Plasma Physics Laboratory)
18/10/2016, 11:25
The nature of ideal-MHD equilibria in three-dimensional geometry is profoundly affected by resonant surfaces, which beget a non-analytic dependence of the equilibrium on the boundary. Furthermore, non-physical currents arise in equilibria with continuously-nested magnetic surfaces and smooth pressure and rotational-transform profiles.
We demonstrate that three-dimensional, ideal-MHD...
Dr
Yongkyoon In
(National Fusion Research Institute)
18/10/2016, 11:45
An extensive study of intrinsic and controlled non-axisymmetric field impacts in KSTAR has enhanced the understanding about non-axisymmetric field physics and its implications, as well as demonstrating the importance of optimal 3-D configurations in resonant magnetic perturbation (RMP)-driven control on edge localized modes (ELMs) in tokamaks. The $n=1$ intrinsic non-axisymmetric field was...
Dr
Oliver Schmitz
(University of Wisconsin - Madison, Department of Engineering Physics)
18/10/2016, 12:05
Exhaust of helium as a fusion born plasma impurity is a critical requirement for future burning plasmas. We demonstrate in this paper that resonant magnetic perturbation (RMP) fields can be used to actively improve helium exhaust features. We present results from the TEXTOR tokamak with a pumped limiter and from the LHD heliotron with the closed helical divertor. The results show an important...
Dr
Gary M. Staebler
(General Atomics)
18/10/2016, 14:00
Two important regimes, observed in non-linear gyrokinetic turbulence simulations, are not well modeled by the TGLF quasilinear model. The first is the Dimits shift regime characterized by a non-linear upshift in the effective critical ion temperature gradient above the linear threshold. The second is the electron temperature gradient (ETG) streamer regime characterized by high electron scale...
Dr
Robert Hager
(Princeton Plasma Physics Laboratory)
18/10/2016, 14:00
Based on the kinetic simulations with the new gyrokinetic neoclassical code XGCa in realistic magnetic separatrix geometry, we developed an improved bootstrap current formula [R. Hager, C.S. Chang, submitted to Phys. Plasmas (2015)] that is much more accurate in steep edge pedestal plasma than the widely used formula by Sauter et al. [O. Sauter et al., Phys. Plasmas 6, 2834 (1999)] while being...
Dr
Robert Budny
(Princeton University)
18/10/2016, 14:00
Experiments to detect alpha heating were performed in TFTR (1994) [1] and in JET (DTE1 1997 [2]. The TFTR results were claimed to be consistent with alpha particle heating of electrons. The JET results were claimed to show that alpha particle heating had been unambiguously observed. Recent papers [3,4] reanalyzed the alpha heating and other discharges from the JET DTE1 using improved TRANSP...
Dr
Zixi Liu
(Princeton Plasma Physics Laboratory / Institute of Plasma Physics, Chinese Academy of Sciences)
18/10/2016, 14:00
The weakly coherent mode (WCM) in I-mode has been studied by six-field two-fluid model based on the Braginskii equations under the BOUT++ framework. The calculations indicate that a tokamak pedestal exhibiting a WCM is unstable to drift Alfven wave (DAW) instabilities and resistive ballooning mode. The nonlinear simulation shows promising agreement with the experimental measurements of WCM....
Dr
Masanori Nunami
(National Institute for Fusion Science)
18/10/2016, 14:00
Gyrokinetic and drift kinetic simulations are carried out to investigate anomalous and neoclassical transport of hydrogen isotope and impurity ions in Large Helical Device (LHD) plasmas.
Turbulent transport in high electron temperature regime, where the trapped electron mode (TEM) is dominant, is a critical issue for future burning plasmas. To clarify an impact of hydrogen isotope species on...
Dr
Nobuhiko Hayashi
(Japan Atomic Energy Agency)
18/10/2016, 14:00
The integrated modeling code TOPICS has been extended to couple impurity transports in core and scrape-off-layer / divertor regions, and applied to predictive modeling of JT-60SA high-beta steady-state plasma with the accumulation of impurity seeded to reduce divertor heat load. Consistent evaluation of impurity transport from the edge to the core clarified the compatibility of impurity...
Dr
Jeff Candy
(General Atomics)
18/10/2016, 14:00
Development of a validated integrated modeling framework is a fundamental research task within the US fusion energy program. A primary component of this framework is an accurate transport model describing the small-scale, gradient-driven plasma microturbulence and its associated cross-field transport. Design and calibration of accurate transport models requires a database of well-converged...
Dr
Sun Hee KIM
(ITER Organization)
18/10/2016, 14:00
Non-activation phase H/He operations in ITER will be important for commissioning of tokamak systems, such as diagnostics, heating and current drive (HCD) systems, coils and plasma control systems, and for validation of techniques necessary for establishing feasible operations. The assessment of feasible HCD schemes at various toroidal fields (2.65-5.3T) has revealed that the previously applied...
Sumire Kobayashi
(FrLPP, FrCNRS)
18/10/2016, 14:00
The interaction between spontaneously formed zonal flows and small-scale turbulence in nonlinear gyrokinetic simulations is explored in a shearless closed field line geometry. It is found that when clear limit cycle oscillations prevail, the observed turbulent dynamics can be quantitatively captured by a simple Lotka-Volterra type predator-prey model. Fitting the time traces of full...
Dr
Yongkyoon In
(National Fusion Research Institute)
18/10/2016, 14:00
An extensive study of intrinsic and controlled non-axisymmetric field impacts in KSTAR has enhanced the understanding about non-axisymmetric field physics and its implications, as well as demonstrating the importance of optimal 3-D configurations in resonant magnetic perturbation (RMP)-driven control on edge localized modes (ELMs) in tokamaks. The $n=1$ intrinsic non-axisymmetric field was...
Dr
Oliver Schmitz
(University of Wisconsin - Madison, Department of Engineering Physics)
18/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Exhaust of helium as a fusion born plasma impurity is a critical requirement for future burning plasmas. We demonstrate in this paper that resonant magnetic perturbation (RMP) fields can be used to actively improve helium exhaust features. We present results from the TEXTOR tokamak with a pumped limiter and from the LHD heliotron with the closed helical divertor. The results show an important...
Dr
Gloria Falchetto
(CEA)
18/10/2016, 14:00
Recent developments and achievements of the EUROfusion Code Development for Integrated Modelling project (WPCD, follow-up of EFDA-ITM-TF), which aims at providing a validated integrated modelling suite for the simulation and prediction of complete plasma discharges in any tokamak, are presented. WPCD develops generic complex integrated simulations, workflows, for physics applications, using...
Dr
Sujin Suwanna
(Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand)
18/10/2016, 14:00
Predictive capability of hydrogenic density and impurity density in L and H-mode plasma is strongly desirable to fully understand behaviors of plasma in tokamak, which can exhibit many modes of transports depending on the conditions of plasma. Combining many modes from turbulent transports, the Multi-Mode Model version 1995 (MMM95) includes coefficients from the Weiland model for the ion...
Dr
Alexei Pankin
(Tech-X Corporation)
18/10/2016, 14:00
The Multi-Mode Model (MMM7.1) for anomalous transport [1] is tested in predictive modeling of temperature profiles of high beta poloidal DIII-D discharges. This new H-mode plasma regime, with high beta poloidal and high plasma currents, has been studied in DIII-D tokamak discharges [2]. The MMM7.1 anomalous transport model includes a combination of contributions based on different transport...
Mr
Manaure Francisquez
(Dartmouth College)
18/10/2016, 14:00
A study of L and H mode-like plasma turbulence in the edge of tokamaks is presented, with an emphasis on characterization of these plasmas in numerical simulations with a new Global Drift-Ballooning (GDB) model. This work employs drift-reduced Braginskii two-fluid equations for electromagnetic low-frequency turbulence and solves them in a global large-aspect ratio annulus centered on the last...
Dr
Shinya Maeyama
(Nagoya University)
18/10/2016, 14:00
Most previous studies on plasma turbulence have assumed scale separation between electron-scale (~ electron gyro-radius) and ion-scale turbulence (~ ion gyro-radius). However, multi-scale turbulence studies by using the latest supercomputers indicated existence of cross-scale interactions and its significant impact on turbulent transport, and are necessary for explaining experimental transport...
Prof.
Yong Xiao
(Institute for Fusion Theory and Simulation)
18/10/2016, 14:00
It has been recently discovered that the trapped electron mode (TEM) may play an important role in the H mode edge plasma for domestic tokamaks such as EAST and HL-2A. The stability and transport for TEM for the edge parameters are studied using large scale gyrokinetic particle simulations. The gyrokinetic simulation reveals the parametric dependences on the wavelength, collisionality and the...
Dr
Sumin Yi
(National Fusion Research Institute, Daejeon, Republic of Korea)
18/10/2016, 14:00
The so-called “spontaneous” or “intrinsic” rotation driven by ion-scale turbulence has been widely observed in tokamaks. If we turn our attention to the electron parallel momentum balance, it is likely that electron-scale turbulence, e.g. electron temperature gradient (ETG) turbulence, can modify the Ohm’s law, hence providing a current source. However, there has been no serious study of an...
Dr
Ihor Holod
(University of California Irvine)
18/10/2016, 14:00
Present understanding of ELM triggering mechanism is mostly based on the peeling-ballooning theory (PBT) often providing sufficiently good pedestal prediction. While PBT is rather empirical, the more comprehensive kinetic description is still required.
In this work we present recent gyrokinetic simulations aimed to identify electromagnetic microinstabilities in the H-mode pedestal region of...
Dr
Mike Kotschenreuther
(Institute for Fusion Studies)
18/10/2016, 14:00
For the first time, electromagnetic gyrokinetic simulations of pedestal transport are reported (inter-ELM). For the JET-ILW (ITER Like Wall) pedestal, nonlinear simulations show that Micro-Tearing Mode (MTM) turbulence produces the bulk of the transport in the steep gradient region, and the combination of MTM, electron temperature gradient (ETG), ion-scale electrostatic turbulence and...
Dr
Sadayoshi Murakami
(Departement Nuclear Engineering, Kyoto University)
18/10/2016, 14:00
The deuterium experiment project from 2017 is planned in LHD, where the deuterium NBI heating beams with the power more than 30MW are injected into the deuterium plasma. Principal objects of this project are to clarify the isotope effect on the heat and particle transport in the helical plasma and to study energetic particle confinement in a helical magnetic configuration measuring triton...
Dr
Michele Romanelli
(UK Atomic Energy Authority)
18/10/2016, 14:00
Along with the construction and operation of ITER, the design of a demonstration thermonuclear fusion reactor (DEMO) is the main goal of current international fusion research. New generation of tokamaks as JT-60SA are meant to provide important information to allow discriminating between different DEMO designs. In particular JT-60SA will explore the possibility of running steady state plasma...
Dr
Elina Militello Asp
(CCFE)
18/10/2016, 14:00
The evolution from X-point formation of ITER H, He and DT plasmas with gas and/or pellet fuelling has been studied for the first time self-consistently with the integrated core and edge suite of codes JINTRAC developed at JET. Our results show that understanding how to optimise fuelling performance is vital to operate ITER and to achieve high fusion yield without exceeding operational limits...
572.
Multi-species ITG-TEM driven turbulent transport of D-T ions and He-ash in ITER burning plasmas
Dr
Motoki Nakata
(National Institute for Fusion Science)
18/10/2016, 14:00
Burning plasmas are composed of multiple ion species such as fuel isotopes(D and T) and He-ash produced by the fusion reaction, and more complex turbulent transport processes are expected in comparison to the single-ion plasmas. Since simultaneous measurements of the kinetic profiles for all species are limited even in experiments, systematic studies on the particle and heat transport by the...
Dr
Tariq Rafiq
(Lehigh University)
18/10/2016, 14:00
Microtearing modes (MTMs) have been identified as a source of significant electron thermal transport in high β tokamak discharges. A model for MTMs that can be installed in integrated whole device predictive modeling codes is needed in order to improve the prediction of electron thermal transport and, consequently, the evolution of the plasma in devices in which MTMs have a significant role. A...
Prof.
Yong-Su Na
(Seoul National University)
18/10/2016, 14:00
We report present status and main results of the ITPA IOS Topical Group activity on the benchmarking of simulations of the core particle transport in ITER baseline ELMy H-mode scenario with the integrated codes which are presently used for the ITER scenario simulations. The ITPA IOS group is pursuing particle transport as an important component of integrated modelling, because the simulations...
Dr
Carlos Paz-Soldan
(Oak Ridge Institute for Science Education)
18/10/2016, 14:00
Measurements and modeling of the plasma response to applied 3D magnetic perturbations – specifically its dependence on collisionality, beta, and rotation – yield new insight into the physics of edge-localized mode (ELM) control and better define the criteria needed to achieve ELM suppression in ITER. ELM control depends on the coupling of the applied field to a stable edge mode that drives...
Dr
Juan Knaster
(IFMIF/EVEDA (F4E))
18/10/2016, 14:00
IFMIF, the International Fusion Materials Irradiation Facility, presently in its Engineering Validation and Engineering Design Activities (EVEDA) phase under the Broader Approach Agreement, will allow accelerated testing of structural materials with fusion relevant neutrons at >20dpa/year in 500cm3.
IFMIF consists of two 125 mA and 40 MeV D+ linear accelerators operating in CW mode. The...
Dr
Stuart Hudson
(Princeton Plasma Physics Laboratory)
18/10/2016, 14:00
The nature of ideal-MHD equilibria in three-dimensional geometry is profoundly affected by resonant surfaces, which beget a non-analytic dependence of the equilibrium on the boundary. Furthermore, non-physical currents arise in equilibria with continuously-nested magnetic surfaces and smooth pressure and rotational-transform profiles.
We demonstrate that three-dimensional, ideal-MHD...
Dr
Jin Yong Kim
(National Fusion Research Institute, Korea (south))
18/10/2016, 14:00
As an effort to clarify the physics origin of the global scaling laws of energy confinement time, a new analysis scheme is first proposed in which the total stored energy is divided into the two parts, one being almost directly decided by the marginal stability property and edge boundary condition through profile stiffness and the other by the profile deviation from marginal one through...
Dr
thawatchai Onjun
(Sirindhorn International Institute of Technology)
18/10/2016, 14:00
The deuterium and tritium are considered as a fuel for nuclear fusion reactors in the future fusion machine, like ITER and DEMOs. Generally, deuterium is applied by gas puffing or pellet injection; whereas tritium can be internally produced from a blanket of reactors, which relies on reactions between 14.1 MeV neutrons from nuclear fusion reactions and lithium as one composite of the blankets....
Dr
Simon Pinches
(ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul-lez-Durance Cedex, France)
18/10/2016, 14:00
The ITER Integrated Modelling (IM) Programme will not only support the ITER Project in the development and execution of the ITER Research Plan (IRP) but also provide support for the design basis of the ITER facility during construction, in particular for diagnostics. Strategically, the ITER IM Programme is implemented using expertise and technologies developed within the ITER Members’ research...
Dr
Clemente Angioni
(Max-Planck-Institut fuer Plasmaphysik)
18/10/2016, 14:00
The validation of current models to predict the transport of a heavy impurity like tungsten in tokamaks is confronted with challenges from both the theoretical and experimental standpoints. Both neoclassical and turbulent transport mechanisms are involved, and have to take into account the impact of poloidal asymmetries, produced by both centrifugal effects and temperature anisotropies caused...
Dr
Irina Voitsekhovitch
(CCFE)
18/10/2016, 14:00
Integrated Modelling (IM) of present experiments and future tokamak-reactor requires numerical tools which can describe spatially small-scale and large-scale phenomena as well as dynamically fast transient events and relatively slow plasma evolution within a reasonably fast computational time. The progress in the optimisation and speed-up of the EU first-principle codes and in the development...
Paolo Piovesan
(Consorzio RFX)
18/10/2016, 14:00
This work investigates the formation of helical core equilibria in toroidal fusion plasmas, focusing on the role of dynamo, or magnetic flux pumping mechanisms in determining the equilibrium current profile. Dynamo effects determine the safety factor profile of the final 3D equilibrium, with important consequences on MHD stability and transport. We compare experimental results from multiple...
Dr
Nopporn Poolyarat
(Department of Physics, Faculty of Science and Technology, Thammasat University, THAILAND)
18/10/2016, 14:00
In this work, a simulation of neoclassical tearing mode (NTM) in JET experiments is considered using a 1.5D BALDUR integrated predictive modeling code with an improved ISLAND. An original ISLAND module [1] for calculating the saturated width of magnetic island caused by a magnetic reconnection is obtained from the NTCC Library [2]. This ISLAND module is then modified to improve a consistency...
Dr
Hyun-Tae Kim
(EUROfusion Consortium JET)
18/10/2016, 14:00
The EUROfusion Consortium is planning deuterium-tritium (D-T) experimental campaigns in 2019 on JET with the ITER-Like Wall (ILW) to address physics issues which are important for ITER-D-T experiments. To achieve the scientific objectives, JET operation should demonstrate 10-15MW of fusion power for at least 5 seconds, a performance never attempted before in fusion-research history. The...
Dr
Mikhail Tsventoukh
(Lebedev Physical Institute RAS)
18/10/2016, 14:00
The formation of large stable plasma gradients, e.g. in form of internal transport barriers, being of a strong both practical and fundamental interest. Normally the larger the gradient the larger the transport, and any deviation due to collective plasma behavior is of great interest.
We have predicted theoretically that there is a strong stabilizing action against convective...
Dr
Apiwat Wisitsorasak
(King Mongkut's University of Technology Thonburi)
18/10/2016, 14:00
Simulations of the plasma in the core and the scrape-off layer (SOL) region are carried out using 1.5D BALDUR integrated predictive modeling code to investigate tokamak plasmas in TFTR reactor operating in low confinement mode (L-mode). In each simulation, the plasma current, temperatures, and density profiles in both core and SOL regions are evolved self-consistency. The plasma profiles in...
Prof.
Hiroshi AZECHI
(Institute of Laser Engineering, Osaka University)
18/10/2016, 14:25
Here we report recent progress of the fast ignition inertial confinement fusion demonstration. Fraction of low energy (< 1 MeV) component of the relativistic electron beam (REB), which efficiently heats the fuel core, increases by the factor of 4 by enhancing pulse contrast of heating laser and removing preformed plasma sources. Kilo-tesla magnetic field is studied to guide the diverging REB...
Dr
Subrata Pradhan
(Institute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat, India)
18/10/2016, 14:50
A. Steady State Superconducting Tokamak (SST-1) is a `operational’ experimental superconducting device since late 2013. Since last IAEA-FEC; SST-1 has been upgraded with Plasma Facing Components being installed and integrated in the vacuum vessel and is getting prepared towards long pulse operations in both circular and elongated configurations. The PFC integration has been completed in August...
Prof.
Xuru Duan
(Southwestern Institute of Physics)
18/10/2016, 15:15
Recent experiments on the HL-2A tokamak have been aimed at the major challenges relevant to ITER operation and fusion energy development. Significant progress has been achieved in many areas, including the first demonstration of high coupling efficiency of LHCD passive-active multi-junction (PAM) antenna in H-mode discharges, pedestal instability and dynamics, ITB formation mechanism,...
Mr
Dmitrii Sarychev
(NRC "Kurchatov Institute")
18/10/2016, 15:40
Review of the recent experimental results obtained on the T-10 tokamak is presented. To decrease the level of light impurities in 2015 both the rail and circular limiters were replaced with ones made of tungsten. The used tungsten type «POLEMA» as well as the technology of its soldering to the bronze substrate are similar to those applied for the production of the ITER divertor tiles. In the...
Prof.
Francisco Castejón
(CIEMAT)
18/10/2016, 16:40
Recent improvements in diagnostics and operation have led to better understanding of 3-D effects on transport and plasma control in the TJ-II stellarator. Impurity transport: Direct measurments of electrostatic potential variations within the same magnetic flux surface in ECRH plasmas are presented. Calculations show that such asymmetries affect impurity accumulation. The asymmetry value and...
Dr
Jonathan Menard
(Princeton Plasma Physics Laboratory)
18/10/2016, 17:05
The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and NSTX Upgrade (NSTX-U) is now the most capable Spherical Torus/Tokamak (ST) in the world program. NSTX-U mission elements include: exploring unique ST parameter regimes to advance predictive capability for ITER and beyond, developing solutions for the plasma-material interface challenge, and advancing the ST as a...
Dr
Andrew Kirk
(Culham Centre for Fusion Energy)
18/10/2016, 17:30
New results from MAST will be presented that focus on validating models in order to extrapolate to future devices. Particular attention will be given to the areas of scenario development, fast particle physics and plasma exhaust.
Understanding filamentary transport across the scrape off layer is a key issue for the design and operation of future devices as it is crucial in determining the...
Prof.
Raymond Fonck
(University of Wisconsin-Madison)
18/10/2016, 17:55
Studies at near-unity aspect ratio offer unique insights into the high confinement (H-mode) regime and support development of novel startup scenarios. Ohmic H-mode operation has been attained at A < 1.3. Edge plasma parameters permit probe measurements of the edge pedestal, including the local current density profile, with high spatial and temporal resolution. H-mode plasmas have standard L-H...
Prof.
Yuichi Takase
(University of Tokyo)
18/10/2016, 18:20
Nationally coordinated research on spherical tokamak (ST) is being conducted in Japan, to strengthen the scientific basis and to broaden future options of ST applications. The research themes to concentrate on are (1) the physics of very high beta plasmas, (2) development of start-up, current drive, and control techniques without the use of the central solenoid (CS), and (3) demonstration of...
Dr
Hiroshi Gota
(Tri Alpha Energy, Inc.)
19/10/2016, 08:30
The world’s largest compact-toroid device, C-2, has been upgraded to C-2U at Tri Alpha Energy to achieve sustainment of field-reversed configuration (FRC) plasmas by neutral-beam (NB) injection (NBI) and edge biasing [1,2], and the C-2U experiment is characterized by the following key system upgrades: increased total NB input power from ~4 MW (20 keV hydrogen) to 10+ MW (15 keV hydrogen) with...
Prof.
Egemen Kolemen
(Princeton University)
19/10/2016, 08:30
A comprehensive adaptive real-time (rt) ELM control system that exploits key properties of ELM physics, Resonant Magnetic Perturbation (RMP) ELM suppression physics, and an extensive set of diagnostic inputs to make rt decisions about the control of multiple actuators to sustain ELM suppression/mitigation is demonstrated at DIII D. The control experiments showed the path dependence and...
Dr
Walter Guttenfelder
(Princeton Plasma Physics Laboratory)
19/10/2016, 08:30
The inward momentum convection or “pinch” observed in many tokamaks can be explained by the Coriolis drift mechanism, with relatively good quantitative agreement found with gyrokinetic predictions of the ion temperature gradient (ITG) instability. Here we attempt to validate this model over a broader range of beta and aspect ratio by extending into the spherical tokamak (ST) plasma regime...
Prof.
Thomas Jarboe
(University of Washington,)
19/10/2016, 08:30
Understanding sustainment of stable equilibria with helicity injection in HIT-SI has led to a simple picture of several tokamak features. Perturbations cause a viscous-like force on the current that flattens the j/B profile, which sustains and stabilizes the equilibrium. An explanation of the mechanism is based on the two properties of stable, ideal, two-fluid, magnetized plasma. First, the...
Prof.
Yasuaki Kishimoto
(Kyouto University)
19/10/2016, 08:30
Profile stiffness and intermittent bursts are the basis in understanding L-mode plasmas. However, why and how these different processes coexist and regulate the transport have not been fully clarified. Here, we presented an overall picture of flux-driven ITG turbulent transport which reveals profile stiffness with self-similarity and SOC type intermittent bursts simultaneously using a...
Dr
Alan Costley
(Tokamak Energy Ltd)
19/10/2016, 08:30
Tokamak Energy Ltd, UK, is developing spherical tokamaks (STs) using High Temperature Superconductor (HTS) magnets as a route to fusion power based on high gain, small size power plants. The paper presents an overview of the continuing advances in technology and modeling, which, together with key engineering developments, support this concept. The ST achieved recognition as a high beta plasma...
Prof.
Tomohiko Asai
(Nihon University)
19/10/2016, 08:30
A repetitively driven compact toroid (CT) injector has been developed for large-sized field-reversed configuration (FRC) facility of the C-2/C-2U primarily for refueling. Pursuit of the FRC as fusion reactor is motivated by highly favorable technological features: extremely high beta (>50%), a natural divertor, and axial mobility allowing separation of start-up and confinement functions....
Dr
Francesca Turco
(Columbia University)
19/10/2016, 08:30
Analysis of ~180 ITER Baseline Scenario (IBS) demonstration discharges in DIII-D provides insight into the cause of the 2/1 disruptive instabilities that limit the duration of these plasmas. Raw MSE data and detailed equilibrium reconstructions show that a larger current profile gradient in the region of the q=2 surface characterises the unstable cases, providing the drive for the 2/1 tearing...
Dr
David Eldon
(Princeton University)
19/10/2016, 08:30
A new control system at DIII-D has stabilized the detached divertor plasma state in close proximity to the threshold for reattachment, thus demonstrating ability to maintain detachment with minimum gas puffing. When the same control system was instead ordered to hold the plasma at the threshold, the resulting T_e profiles separated into two groups with one group consistent with marginal...
Susan Leerink
(Aalto University)
19/10/2016, 08:30
Turbulent transport and flow dynamics in Ohmic FT-2 tokamak plasmas are investigated. Measurements utilize highly localized state-of-the art backscattering while the
turbulence simulations are performed with the global full-f nonlinear code ELMFIRE. The role of the geodesic acoustic mode in regulating turbulent transport is studied. Special emphasis is given to the isotope effect observed in...
Dr
Robert Granetz
(MIT)
19/10/2016, 08:30
To address the challenge of disruption prediction, we
have created large disruption warning databases for both
Alcator C-Mod and EAST by compiling values for a number
of proposed disruption-relevant parameters sampled at
many different times throughout all plasma discharges,
disruptive and non-disruptive, during the 2015 campaigns
on the respective machines. The...
Dr
Alexei Beklemishev
(Budker Institute of Nuclear Physics SB RAS)
19/10/2016, 08:30
A new efficient method of magnetic confinement is suggested for use in linear traps with extremely high plasma pressure. While pressure grows, the equilibrium in a linear trap changes in such a way that the effective mirror ratio increases, and, as a result, the axial particle and energy confinement becomes gas-dynamic and improves linearly with mirror ratio. This effect is due to diamagnetic...
Dr
John deGrassie
(General Atomics)
19/10/2016, 08:30
A dimensionless empirical scaling for intrinsic toroidal rotation is given; MA~βNρ*, where MA is the toroidal velocity divided by the Alfvén velocity, βN the usual normalized β value, and ρ* is the ion gyroradius divided by the minor radius. This scaling is in agreement with experimental data from DIII-D, and also incorporates some published data from C-Mod and JET. The velocity used in this...
Mr
Daisuke Shirakid
(Oak Ridge National Laboratory)
19/10/2016, 08:30
Experiments on the DIII-D and Alcator C-Mod tokamaks show that disruption mitigation by massive gas injection (MGI) and shattered pellet injection (SPI) of high-Z impurities remain effective in the presence of large pre-existing MHD instabilities. Rotating and locked magnetic islands will precede a large fraction of disruptions in ITER, making their impact on disruption mitigation a critical...
Prof.
Saskia Mordijck
(The College of William and Mary)
19/10/2016, 08:30
In this paper we will show that particle confinement is determined by changes in turbulence characteristic outside mid-radius up to the top of the pedestal in DIII-D H-mode plasmas. We find that the Electron Cyclotron Heating (ECH) density pump-out at low collisionality is the result of an increase in turbulence drive from ρ=0.7-0.9. The frequency of the mode and thus the turbulence type...
Dr
John Omotani
(Department of Physics, Chalmers University of Technology)
19/10/2016, 08:30
The accessibility and performance of the H-mode are critical to tokamak fusion reactors. While the physics of the pedestal is complicated and far from fully understood, it is clear that flow shear plays an important role. One of the mechanisms that may regulate flow velocity in the plasma edge is momentum transport by neutrals. Due to their high cross-field mobility they may be the most...
Dr
Thomas W. Petrie
(General Atomics)
19/10/2016, 08:30
We identify major challenges to reducing divertor heat flux in high power, high performance near-double null DIII-D plasmas, while still maintaining sufficiently low
density to allow for application of RF heating. The plasmas discussed here are characterized by: β_N ≅ 3–4, H_98 ≅ 1.5–1.7, dR_SEP ≅ -5 mm, and P_IN up to 20 MW. The scaling of the peak heat flux (q⊥p) at the outer target of the...
Mr
Chan-Yong An
(Soongsil University)
19/10/2016, 08:30
Turbulent plasma transport is an important issue in the confinement of the fusion plasmas. E×B nonlinear flux plays a deciding role in redistributing the energy and the momentum. In the case of the isothermal plasma the particle flux Γ is the fundamental measure of the turbulent transport. In the fusion plasma where the particle collisions are relatively rare the plasma is near the adiabatic...
Dr
Rajaraman Ganesh
(Institute for Plasma Researh, Bhat Village, Gandhinagar 382428, Gujarat, INDIA)
19/10/2016, 08:30
Turbulent transport of energy, particles and momentum is
one of the important limiting factors for long time
plasma confinement. Modern kinetic study using
gyrokinetic formalism and simulation has progressed
to identify several microinstabilities that cause ion
and electron thermal transport. Typically, these have
been ballooning parity modes such as the ITG, KBM and
ETG modes...
Dr
Silvana Nowak
(IFP-CNR)
19/10/2016, 08:30
The modification of low toroidal plasma rotation under application of central EC power injection with possible onset of neoclassical tearing modes (NTM) is an important issue for plasma confinement and for future devices (ITER will be characterized by a low rotation). In low collisionality regime and PEC/Poh >1 TCV experiments central co-ECCD was observed to modify the toroidal plasma rotation...
Dr
Thawatchai Onjun
(Sirindhorn International Institute of Technology)
19/10/2016, 08:30
This work aims to investigate the effects of perturbations of heat and particle sources on the formations of edge transport barrier (ETB) and on the hysteresis properties at the L-H-L transitions in the framework of bifurcation concept. The formation of transport barriers is studied via the combination of thermal and particle transport equations, which also includes neoclassical and anomalous...
Dr
JaeChun Seol
(National Fusion Research Institute)
19/10/2016, 08:30
KSTAR provides a great environment to carry out the NTV study in that the intrinsic error fields and the toroidal field ripples are very small in magnitude, and asymmetric magnetic fields can be added by the in-vessel coil current on demand. In this paper, we report both theoretical and experimental studies on NTV in KSTAR. It is shown that the radial transport of the toroidal angular...
Dr
Michael Van Zeeland
(General Atomics)
19/10/2016, 08:30
Localized electron cyclotron heating (ECH) can have a dramatic impact on neutral beam driven Alfvén eigenmode (AE) activity in DIII-D plasmas. The most common effect, which is explained here for the first time, is a shift in the dominant observed modes from a mix of reversed shear Alfvén eigenmodes (RSAEs) and toroidicity induced Alfvén eigenmodes (TAEs) to a spectrum of weaker TAEs when ECH...
Prof.
Taik Soo Hahm
(Seoul National University)
19/10/2016, 08:30
Starting from the modern bounce-kinetic formalism, [1] a two-point equation which properly describes turbulent eddies associated with trapped electrons is systematically derived in general tokamak geometry. Trapped electron precession shear, as well as ExB shear, is naturally included in the derivation. Our two-point analysis, using moments of separation between the two points, reveals that...
Dr
John Wright
(MIT - PSFC)
19/10/2016, 08:30
Recent experiments on Alcator C-Mod using a small fraction of 3He added to a H(D) plasma have demonstrated efficient ion cyclotron radio frequency (ICRF) heating and indications of MeV 3He tail temperatures. For high toroidal magnetic field B0=8 T discharges with D majority, 3He minority absorption is typically used and has low single pass absorption compared to the H minority absorption...
Dr
Robert Pinsker
(General Atomics)
19/10/2016, 08:30
Experiments have begun in DIII-D to evaluate non-inductive current drive by the Landau absorption of a toroidally-directive spectrum of helicon waves (also known as 'very high harmonic fast waves', 'fast waves in the lower hybrid range of frequencies', or 'whistlers'). Modeling has shown [1] that non-inductive current drive at mid-radius (ρ~0.5) should be achievable in DIII-D with fast waves...
Dr
Jeffrey Levesque
(Columbia University)
19/10/2016, 08:30
The HBT-EP research program aims to: (i) quantify wall-stabilized kink mode dynamics and multimode response to applied magnetic perturbations, (ii) understand the relationship between control coil configuration, conducting and ferromagnetic wall effects, and active feedback control, and (iii) explore advanced feedback algorithms. We present an overview of planned research activities for the...
Dr
Yasuhiro Idomura
(Japan Atomic Energy Agency)
19/10/2016, 08:30
A new hybrid kinetic trapped electron model [Y. Idomura, J. Comput. Phys. 313, 511 (2016)] is developed for electrostatic full-f gyrokinetic simulations. The model is verified by computing the ion and electron neoclassical transport and the linear ion temperature gradient driven trapped electron mode (ITG-TEM) stability, in which collisional TEM stabilization shows an isotope effect. An impact...
Dr
Seikichi Matsuoka
(Japan Atomic Energy Agency)
19/10/2016, 08:30
The neoclassical toroidal viscosity (NTV) caused by a non-axisymmetric magnetic field perturbation is one of the key issues for the prediction and control of the plasma performance and/or stabilities, since it can play an important role in a momentum balance which determines a plasma rotation. However, there remains a severe discrepancy with regard to the NTV prediction; the so-called...
Dr
Lei Qi
(National Fusion Research Institute, Daejeon, Korea)
19/10/2016, 08:30
Nonlinear bounce-averaged kinetic theory[B.H. Fong and T.S. Hahm, Phys. Plasmas 6, 188 (1999)] is used for magnetically trapped electrons for the purpose of achieving efficient gyrokinetic simulations of Trapped Electron Mode (TEM) and Ion Temperature Gradient mode with trapped electrons (ITG-TEM) in shaped tokamak plasmas. Bounce-averaged kinetic equations are explicitly extended to shaped...
Dr
Michael Leconte
(National Fusion Research Institute)
19/10/2016, 08:30
Controlling Edge Localized Modes (ELMs) is very important for ITER, and a well-tested way to achieve this is by using external coils to generate Resonant Magnetic Perturbations (RMPs), demonstrated on several tokamaks [1-4]. The working hypothesis for the origin of ELM suppression is that RMPs increase transport in the pedestal, thus lowering the pressure-gradient below the ideal-MHD...
Prof.
Eugenio Schuster
(Lehigh University)
19/10/2016, 08:30
Recent experiments on DIII-D demonstrate the potential of physics-model-based q-profile control to improve reproducibility of plasma discharges. A combined feedforward+feedback control scheme was employed to optimize the current ramp-up phase by consistently achieving target q profiles (Target 1: qmin=1.3, q95=4.4; Target 2: qmin=1.65, q95=5.0; Target 3: qmin=2.1, q95=6.2) at prescribed times...
Dr
Masaki Nishiura
(The University of Tokyo)
19/10/2016, 08:30
While the stable high-beta (~ 1) confinement by a dipole magnetic field was successfully demonstrated with high-temperature electrons (Te > 10 keV) [1, 2], the heating of ions was a challenge. We have made two major progresses in this direction. (i) We developed a system for ion cyclotron resonance of frequency (ICRF) heating, and demonstrated the active heating of ions by launching a slow...
Dr
Kenji Imadera
(Kyoto University)
19/10/2016, 08:30
Profile stiffness is a long standing problem, which may limit the overall performance of H-mode plasmas. In the JET experiment, while strong temperature profile stiffness is observed around the nonlinear threshold of ion temperature gradient, it can be greatly reduced by co-current toroidal rotation in weak magnetic shear plasma.
To understand such a mitigation mechanism of the stiffness, we...
Dr
Mikhail Malkov
(University of California, San Diego)
19/10/2016, 08:30
H-mode operation is the regime of choice for good confinement. Access to and sustainability of the H-mode requires understanding of the L $\rightarrow$ H transition power threshold and the related problem of hysteresis. To predict ITER transitions, one must also understand low collisionality, electron-heated regimes.
In this paper, we discuss a.) L $\rightarrow$ H power threshold scaling...
Diego del-Castillo-Negrete
(Fusion Energy Division. Oak Ridge National Laboratory)
19/10/2016, 08:30
The quantitative understanding of the role of magnetic field stochasticity on transport is critical for the confinement of fusion plasmas. Specific problems of interest include the control of ELMs by resonant magnetic perturbations and the assessment of heat fluxes at the divertor. Here we present direct numerical simulations of the time dependent parallel heat transport equation modeling heat...
Dr
K. C. Shaing
(Engineering Physics Department, University of Wisconsin)
19/10/2016, 08:30
Theory for neoclassical toroidal plasma viscosity is to describe the transport processes, including particle, momentum, and energy transport fluxes in real tokamaks with broken symmetry. The predictions of the theory are in agreement with the numerical results in all collisionality regimes in the large aspect ratio limit. The theory has since been extended to finite aspect ratio tokamaks. The...
Prof.
Patrick Diamond
(University of California San Diego)
19/10/2016, 08:30
Negative viscosity phenomena in which turbulence driven by the heat flux couples its energy to large scale structure, is a familiar and, in fact, necessary element in the success of magnetic fusion. Two prime examples of negative viscosity phenomena are zonal flow formation, where drift wave turbulence drives mesoscale shear flows which regulate large scale eddys, and intrinsic torque, where...
Dr
Masatoshi Yagi
(National Institutes for Quantum and Radiological Science and Technology, Rokkasho Fusion Institute)
19/10/2016, 08:30
The transient transport events are observed in toroidally magnetic confinement devices. For example, the cold pulse experiment shows a rapid transient increase of electron temperature in the plasma core in response to an abrupt cooling at the edge. Understanding the nonlocal transport is important to control plasma core and/or fuel supply in ITER and DEMO. The nonlocal particle transport has...
Dr
Naohiro Kasuya
(Kyushu University)
19/10/2016, 08:30
Recent simulations in three-dimensional (3-D) magnetically confined plasmas show various aspects of plasma turbulence, and numerical diagnostics using 3-D simulation data of helical plasmas have been carried out. Here we present results of turbulence analyses (i) in simplified geometry for detailed nonlinear mechanism of heat transport, and (ii) in real 3-D geometry for comprehensive...
Richard Majeski
(Princeton Plasma Physics Lab)
19/10/2016, 08:30
Discharges with high edge electron temperatures and flat radial electron temperature profiles, extending to the last closed flux surface, and into the low field side scrape-off layer, have now been achieved in the Lithium Tokamak eXperiment (LTX), with lithium-coated walls. Flat temperature profiles are a long-predicted consequence of low recycling boundary conditions [S. Krasheninnikov, L....
Dr
Michio Okabayashi
(Princeton Plasma Physics Laboratory)
19/10/2016, 08:30
Resistive and quasilinear 3D modeling is improving the understanding of recent experiments [1] carried out in DIII-D and RFX-Mod, in which disruptions were prevented by means of electromagnetic torque applied by non-axisymmetric (3D) coils. We will report the 3D aspects of experimental observations in comparison with finite resistivity (tearing) response by MARS-F and a time dependent torque...
Dr
Brian LaBombard
(MIT Plasma Science and Fusion Center)
19/10/2016, 08:30
The improved impurity screening characteristics of the high-field side scrape-off layer to local impurity sources, previously reported for single null geometries, is found to be retained in double null configurations - strengthening the argument for locating current drive and heating actuators on the high-field side.
The high-field-side (HFS) scrape-off layer (SOL) is known to exhibit...
Dr
Aaron Hossack
(University of Washington)
19/10/2016, 08:30
The Helicity Injected Torus - Steady Inductive (HIT-SI) program studies efficient, steady-state current drive for magnetic confinement plasmas using a novel experimental method. Stable, high-beta spheromaks have been sustained using steady, inductive current drive which is significantly more efficient than RF or neutral beams when scaled to a reactor. Externally induced loop voltage and...
Dr
Milan Rajkovic
(University of Belgrade, Institute of Nuclear Sciences Vinca)
19/10/2016, 08:30
Recently, we have developed a comprehensive mathematical and computational framework for the analysis and quantification of self-organization [1]. Application of this method may resolve some of the important issues of fusion plasmas such as prediction of changes in the pattern formation and transport properties, to name a few. We assume that the system self-organizes if its complexity...
Dr
Mitsuru Honda
(Japan Atomic Energy Agency)
19/10/2016, 08:30
Capabilities of the integrated framework consisting of TOPICS, OFMC, VMEC and FORTEC-3D, have been extended to calculate toroidal rotation in fully non-axisymmetric perturbed magnetic fields, for demonstrating operation scenarios in actual tokamak geometry and conditions. It was found for the first time that the toroidally localized perturbed fields due to the test blanket modules (TBMs) and...
Dr
Daniele Bonfiglio
(Consorzio RFX, Padova, Italy)
19/10/2016, 08:30
Recent theoretical studies of the reversed-field pinch (RFP) have demonstrated the possibility of stimulating new quasi-single helicity (QSH) regimes by allowing a small helical deformation of the magnetic boundary. In particular, 3D nonlinear MHD modeling predicted QSH states based on non-resonant helicities are predicted to be more resilient to magnetic stochasticity induced by secondary...
Dr
Yohji Seki
(National Institutes for Quantum and Radiological Science and Technology)
19/10/2016, 08:30
A. R&Ds for starting operation with a full- tungsten (W) ITER (INB-174) divertor have been enhanced by recommendation of the ITER council since 2011. Japan Atomic Energy Agency (JAEA) as Japanese Domestic Agency (JADA) and the ITER organization (IO) have been actively working on the development and demonstration on the full-W ITER divertor under the framework of the task agreement. JAEA is in...
Prof.
Yasushi Ono
(University of Tokyo)
19/10/2016, 08:30
A series of merging experiments: TS-3, TS-4 and MAST made clear the promising characteristics of reconnection heating for merging formation of high-beta spherical tokamak (ST) and field-reversed configuration (FRC). We found the reconnection outflow produces MW-class (<30MW in TS-3) ion heating power based on the findings:
(i) its ion heating energy that scales with square of the reconnecting...
Prof.
Luis Garcia
(Universidad Carlos III de Madrid)
19/10/2016, 08:30
Turbulence induced transport is one of the outstanding physics problems in plasma physics. In the turbulence induced transport issue, we began with the identification of turbulent flow structures using topological and geometric techniques on the framework of resistive MHD. The structure of the flow is filamentary. The filaments are vortices that are linked to the rational surfaces. At a given...
Dr
Helen Kaang
(National Fusion Research Institute)
19/10/2016, 08:30
We study how electromagnetic (EM) fluctuations impact on residual Reynolds stress in the context of the quasi-linear theory. Two-fluid model is employed to describe EM ion temperature gradient turbulence. Analyses show that not only the conventional parallel residual stress but also additional stress due to EM fluctuations strongly increase with plasma beta (=plasma thermal energy/magnetic...
Prof.
Uri Shumlak
(UsUWash)
19/10/2016, 08:30
The sheared-flow stabilized Z-pinch has been experimentally demonstrated to produce long-lived plasmas that satisfy radial force balance and are stable for thousands of exponential growth times. The sheared-flow stabilized Z-pinch has the potential to lead to a compact plasma confinement device that scales to fusion conditions. The stabilizing effect of a sheared axial flow on the m=1 kink...
Prof.
Geert Verdoolaege
(Ghent University)
19/10/2016, 08:30
The standard scaling law for the global energy confinement in H-mode tokamak plasmas provides a guideline for machine design and planning of operational scenarios. In addition, it is used as a benchmark to assess the quality of confinement in present experiments. However, owing to the complexity of the multi-machine data sets from which the scaling is derived, the coefficient estimates may...
Dr
Anthony W. Leonard
(USA)
19/10/2016, 08:30
Experiments on DIII-D have advanced the physics basis for simultaneously achieving a high pressure H-mode pedestal for high core plasma confinement with a highly dissipative divertor for protection of plasma facing components in future reactor tokamaks. These studies show achievement of this goal is governed by the coupling of several pedestal and divertor processes including: 1) the pedestal...
Dr
Sergey Medvedev
(Keldysh Institute of Applied Mathematics)
19/10/2016, 08:30
Fusion research has to solve the power handling problem toward fusion demonstration reactor (DEMO). Tokamak plasma with negative triangularity and an outboard divertor X-point may offer such an opportunity as an innovative concept. The present paper extends this concept investigating single null negative triangularity tokamak (SN-NTT). Double null negative triangularity tokamak (DN-NTT)...
Dr
Vsevolod Soukhanovskii
(Lawrence Livermore National Laboratory)
19/10/2016, 08:30
Analyses of snowflake (SF) divertor experiments in NSTX and DIII-D show that the SF divertor can increase edge magnetic shear and modify pressure profiles of the H-mode pedestal enabling pedestal stability control while maintaining good H-mode confinement (H_98y2~1). The scrape-off layer (SOL) geometry modifications lead to reduced peak temperature of plasma-facing components (PFC) via...
Dr
Aaron Sontag
(Oak Ridge National Laboratory)
19/10/2016, 08:30
Core transport models predict that fusion power scales roughly as the square of the pressure at the top of the pedestal, so understanding the effects that determine pedestal structure in steady-state operational scenarios is important to project steady-state tokamak operational scenarios developed in DIII-D to ITER and other devices. Both experiments and modeling indicate that SOL conditions...
Ms
Linda Sugiyama
(Laboratory for Nuclear Science, UsMIT)
19/10/2016, 08:30
A large amount of evidence suggests that the bright loops that are
regularly observed in the sun's corona are magnetic flux ropes that confine plasma,
tied at both ends to structures in the photosphere.
Due to the difficulties of observation,
their steady states have never been explained.
Coronal loops resemble partial magnetic tori and
ideas from the equilibrium and stability of...
Dr
Jeremy Hanson
(Columbia University)
19/10/2016, 08:30
DIII-D experiments demonstrate high-performance, negative central shear (NCS) equilibria with enhanced stability when the minimum safety factor qmin exceeds 2, qualitatively confirming theoretical predictions of favorable stability in the NCS regime. The discharges exhibit good confinement and performance (H89 = 2.5, H98,Y2 = 1.5, βN = 4), and are ultimately limited by the ideal-wall...
Dr
Wendell Horton
(Institute of Fusion Studies, The University of Texas at Austin)
19/10/2016, 08:30
First stability and transport in RF driven plasmas in ITER-like geometries are investigated using new kinetically modified MHD stability equations analyzed with theory and advanced simulations. Extended MHD stability analysis describes in detail the outer most closed flux surfaces inside the magnetic separatrix where ions and electrons dynamics differ. The new physics includes the effect of...
Dr
Julio Martinell
(Nuclear Sciences Institute, National Autonomous University of Mexico)
19/10/2016, 08:30
In the first part we study the magnetic equilibrium of TJ-II using the VMEC code together SIESTA MHD code. The pressure profiles determine island geometry. For each island width we obtain the associated MHD energy in order to find a correlation between them and identify an island width that has better stability properties.
A dynamical analysis of magnetic islands is aimed at explaining the...
Prof.
Miklos Porkolab
(MIT)
19/10/2016, 08:30
Experimental results are presented where the macroscopic plasma conditions were manipulated by external actuators, such as injection of medium to low Zi impurity gases with ohmic heating (Alcator C-Mod) to dilute the main deuterium ion species, or deploy a different mix of NBI and ECH heating methods (DIII-D), thus enabling us to study the resulting changes in transport and turbulence....
Dr
Dmitri Orlov
(University of California San Diego)
19/10/2016, 08:30
In this work we show that the application of a “square wave” n=1 toroidal perturbation on DIII-D and KSTAR leads to significant n=3 toroidal sidebands. In the vacuum model, these n=3 sidebands assist in creation of wide stochastic field in the edge of the plasma. In KSTAR, the n=3 sideband fields create vacuum islands in the right places to extend the vacuum island overlap width to more than...
Mr
Robert Chahine
(LMFA, FrECL)
19/10/2016, 08:30
A notable influence of the shape of the plasma on the dynamics of RFPs is clearly illustrated by simulations of fully nonlinear visco-resistive magnetohydrodynamics. The axial mode-spectrum is qualitatively changed in cylinders with elliptic cross-section. The results suggest that shaping will change, and possibly improve the confinement of RFPs.
Dr
Sung Sik Kim
(National Fusion Research Institute)
19/10/2016, 08:30
Development of a self-consistent, core-edge integrated simulation capability is a long standing problem in fusion simulation program. Such capability would yield insight into questions related to global profile dynamics originating from L to H transition and internal transport barrier formation. Starting from a tokamak edge plasma simulation code, BOUT++ has evolved into a versatile framework...
Dr
Robert S. Wilcox
(Oak Ridge National Laboratory)
19/10/2016, 08:30
When resonant magnetic perturbations are applied to suppress edge localized modes using the internal coil set in the DIII-D tokamak with toroidal mode number n=3, measurements of density fluctuations at toroidally separate locations using beam emission spectroscopy (BES) and Doppler back-scattering show larger fluctuation amplitudes in one toroidal phasing than the other. This relationship is...
Dr
Yusuke Kosuga
(Institute for Advanced Study, Kyushu University)
19/10/2016, 08:30
Recent progress on the modeling of turbulent transport of parallel flow momentum is reported. Compared to the Reynolds stress or the convective term, the role of the triplet (nonlinear) flux is emphasized. The triplet term is calculated in the wave turbulence limit. The result indicates that the nonlinear flux becomes important compared to the stress term in the region with the steep intensity...
Dr
George McKee
(University of Wisconsin-Madison)
19/10/2016, 08:30
Low-wavenumber density fluctuations exhibit rapidly changing characteristics during the current ramp-up phase of ITER-like discharges that reflect a complex interaction between evolving electron transport, safety factor (q) and kinetic profiles and low-order rational surfaces. These measurements and analysis can explain discrepancies between various transport models and measurements during the...
Mr
L. Schmitz
(University of California-Los Angeles)
19/10/2016, 08:30
Understanding flow drive and damping across the relevant ion collisionality range is crucial for connecting the L-H transition trigger physics to the macroscopic L-H power threshold scaling. This is of utmost importance for minimizing the auxiliary heating power required for H-mode access in burning plasmas. It is shown here for the first time that the main-ion poloidal flow acceleration is...
Dr
Chris McDevitt
(Los Alamos National Laboratory)
19/10/2016, 08:30
In this work we discuss the efficiency of various turbulent mechanisms for modifying the plasma current. The first mechanism results from the establishment of an equilibrium between trapped and passing electrons due to resonant scattering by microturbulence. This mechanism is closely analogous to the familiar neoclassical bootstrap current except that it relies on wave-particle interactions to...
Dr
Weixing Wang Wang
(Princeton University Plasma Physics Laboratory)
19/10/2016, 08:30
The main focus of this paper is on developing physical understanding and a first-principles-based model for predicting intrinsic rotation profiles in magnetic fusion experiments, including ITER. It is shown for the first time that turbulent fluctuation-driven residual stress can account for both the shape and magnitude of the observed intrinsic toroidal rotation profile. Specifically, nonlinear,...
Morgan Shafer
(Oak Ridge National Laboratory)
19/10/2016, 08:30
Measurements of islands induced by resonant magnetic perturbations (RMP) in the core of a L-mode DIII-D plasma are used to challenge predicted screening trends from linearized extended MHD and to examine modeling of the nonlinearly saturated island state. In these plasmas, fine torque scans reveal that large n=1 RMP-induced islands are present at multiple mode-rational surfaces at low...
Dr
Guilhem Dif-Pradalier
(CEA, IRFM, F-13108 Saint-Paul-lez-Durance cedex, France)
19/10/2016, 08:30
Large-scale global organisation of turbulence has attracted persistent interest in fusion plasmas as a means to control transport and access improved confinement. It has practical consequences on zonal flow formation and sustainment, on front propagation—a natural tendency in heat flux-driven turbulence—or on the spreading of turbulence in regions of quasi-linear stability.
In this paper we...
Dr
Brent Covele
(General Atomics)
19/10/2016, 08:30
Highly flared, highly flux-expanded X-Divertors (XDs) on DIII-D detached at a lower Greenwald fraction and higher pedestal pressure than standard divertors (SDs), strongly reducing problematic plasma exhaust at the target, allowing for improved control of the detachment front, and maintaining a higher-confinement H-mode necessary for a future fusion reactor. XDs exhibit lower parallel ion...
Dr
Klaus Hallatschek
(Max-Planck-Institute for Plasma Physics)
19/10/2016, 08:30
Fluid turbulence simulations cannot describe the kinetic effects due to the scarcity of collisions in tokamak plasmas but allow for much higher spatial resolution than kinetic simulations and become more reliable at large collision frequencies. Conversely, gyrokinetic simulations, the standard in current tokamak turbulence modeling, cannot be performed with the full set of nonlinearities that...
Mr
Kaiming Feng
(Southwestern Institute of Physics)
19/10/2016, 08:50
The current design of Chinese Heilum-cooled Ceramic Breeder Test Blanket Module (HCCB TBM) with 1×4 configuration scheme, it includes 4 independent breeding sub-modules with 10mm gap (for thermal expansion) between each other along the poloidal direction. Tthese sub-modules are connected with a big back plate containing auxiliary connection pipes for coolant and purge gas, shear keys and...
Dr
Italo Ricapito
(Fusion for Energy)
19/10/2016, 09:10
The general objective of the ITER TBM Program is to provide the first experimental data on the performance of the breeding blankets in the integrated fusion nuclear environment. Such data are essential to design and predict the performance of DEMO and future fusion reactors.
To achieve this objective, the TBM programme will have to:
• test and validate technologies and materials in a...
Mr
Abhishek Saraswat
(InIPR)
19/10/2016, 09:30
Liquid Lead Lithium (Pb-16Li) is of primary interest as one of the candidate materials for coolant fluid and tritium breeder in liquid metal blanket concepts relevant to fusion power plants. For effective and reliable operation of such high temperature liquid metal coolant systems, monitoring and control of critical process parameters like pressure, level, temperature and flow is essential....
Dr
Masayuki Ono
(PPPL/Princeton University)
19/10/2016, 09:50
Steady-state fusion power plant designs present major divertor technology challenges, including high divertor heat flux both in steady-state and during transients. In addition to these concerns, there are the unresolved technology issues of long term dust accumulation and associated tritium inventory and safety issues. It has been suggested that radiation-based liquid lithium (LL) divertor...
Dr
Adam McLean
(Lawrence Livermore National Laboratory)
19/10/2016, 10:45
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
A comprehensive experimental campaign at DIII-D has advanced understanding and modeling of the effects of drifts and radiating species in diverted plasma up to ITER-relevant collisionality. Unique diagnostic capabilities are employed to show directly that plasma drifts lead to in/out asymmetries as well as shifts in radial parameter profiles throughout the divertor legs, and are a critical...
Dr
Daniel Carralero
(IPP Garching)
19/10/2016, 11:05
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
Heat and particle transport onto plasma-facing components is a key issue for next generation tokamaks, as it will determine the erosion levels and the heat loads at the main chamber first wall. In the Scrape-off Layer (SOL), this transport is thought to be dominated by the perpendicular convection of filaments. In this work, we present recent experiments which have led to an improved picture...
Dr
Choong-Seock Chang
(Princeton Plasma Physics Laboratory)
19/10/2016, 11:25
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Oral
The edge gyrokinetic code XGC1 shows that the divertor heat flux width λq in between ELMs of Type I ELMy H-modes in two representative types of present tokamaks (DIII-D type for conventional aspect ratio and NSTX type for tight aspect ratio) is set mostly by the ion neoclassical orbit spread, which is proportional to 1/Ip, while the blobby turbulent spread plays a minor role. This explains...
Dr
Holger Reimerdes
(Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC))
19/10/2016, 11:45
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
Present research towards a plasma exhaust solution for a fusion power plant aims at validating edge physics models to strengthen the predictive capabilities and improving the operating regime and the divertor configuration. The TCV tokamak is used in particular to investigate to what extent geometric modifications of the configuration can affect the plasma exhaust performance by decreasing the...
Dr
Ilya Senichenkov
(Saint Petersburg State Polytechnical University)
19/10/2016, 12:05
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Oral
Our current understanding of divertor physics indicates that at least partial detachment will be a necessary condition for operation of future fusion power devices such as ITER, DEMO and beyond. In recent years a divertor operation with complete detachment was achieved in full tungsten ASDEX Upgrade with nitrogen seeding [Potzel et al Nucl. Fusion 54 (2014) 013001, Reimold et al Nucl. Fusion...
Prof.
Jorge Alberto González Guevara
(Universidad Autónoma de Nuevo León)
19/10/2016, 14:00
An important system into the magnetic confinement devices to obtain appropriate knowledge on plasma behavior in nuclear fusion is the electron cyclotron resonance heating (ECRH). We present the preliminary design of our source for ECRH system applied in our Tokamak device, a gyrotron device 60 GHz-300 kW which is currently developed by the Fusion Research Group (GIF, Spanish acronyms) at the...
Dr
Ronald E. Waltz
(General Atomics)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Local nonlinear gyrokinetic code GYRO [1] simulations of energetic particle driven low-n Alfven eigenmodes embedded in high-n microturblence have motivated a local critical gradient model (CGM) for stiff energetic particle (EP) transport from Alfven eigenmodes (AEs). The critical gradient in the EP density (or pressure) gradient identified by the local linear low-n AE growth exceeding the...
Dr
Yuri Petrov
(CompX)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The finite-difference bounce-average Fokker-Planck (FP) code CQL3D [R.W. Harvey and M. McCoy, "The CQL3D Fokker Planck Code"] has been upgraded to include the Finite-Orbit-Width (FOW) effects. This is achieved by transforming the FP equation written in canonical action variables to another set of Constant-Of-Motion (COM) coordinates. A distinctive feature of our approach from that used by...
Dr
Makoto Sasaki
(Research Institute for Applied Mechanics Kyushu University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A new branch of geodesic acoustic modes (GAMs) driven by the magnetic drift motion of fast ions is presented. An effective ion heating mediated by the new branch is expected. Strong ion Landau damping is attributed to the eigenfunction of the new branch, which has steep poloidal gradients. The analysis is based on a gyrokinetic model. The gyrokinetic equation for the fast ions has two kinds of...
Dr
Amanda Hubbard
(Massachusetts Institute of Technology, Plasma Science and Fusion Center)
19/10/2016, 14:00
Significant progress has been made on Alcator C-Mod in expanding the configurations and conditions for which the I-mode regime can be accessed and maintained and understanding the physics which underlies the transport improvement. An important result from multidevice studies is that the power threshold for I-mode has only a weak dependence on BT, while the upper power limit increases with BT,...
Dr
James Myra
(Lodestar Research Corporation)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Heating and current drive by ion cyclotron range of frequency (ICRF) waves is expected to play an increasingly important role as tokamak research progresses towards the reactor regime. The basic heating and current drive interactions of ICRF waves with the core plasma are well understood, and sophisticated modeling tools are available. In contrast, the ability to understand, predict and...
Dr
Hyun-Seok Kim
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Advanced tokamak operations, promising candidates for DEMO operations, require control of plasma profiles to establish and to sustain the enhanced energy confinement and the non-inductive current fraction. The safety factor (q) profile and the electron temperature (Te) profile control have to be controlled to access and maintain the advanced operation modes and to improve controllability of...
Dr
Jun Gyo Bak
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The investigation of poloidal halo current (HC) Ih flowing along the support structures for plasma facing components (PFCs) during the vertical displacement event (VDE) under the toroidal magnetic field BT is required for the estimate of Ih x BT force on the structures in the KSTAR tokamak because it can be expected that the force will cause damages on the structures in the KSTAR when plasma...
Dr
Kimin Kim
(Korea Advanced Institute of Science and Technology)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Toroidal rotation braking by neoclassical toroidal viscosity driven by non-axisymmetric (3D) magnetic fields, called magnetic braking, has great potential to control rotation profile, and thereby improve tokamak stability and performance. In order to characterize magnetic braking in various 3D field configurations, dedicated experiments have been carried out in 2015 campaign, applying a...
Dr
John Berkery
(Columbia University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A comprehensive approach to the prevention of disruption of fusion plasmas in tokamaks begins with identifying disruption event chains and the specific physics elements which comprise those chains. Then, if the events in the disruption chains can be forecast, cues can be provided to an avoidance system to break the chain. Within this framework, we examine the characterization and forecasting...
Mr
Min-Keun Bae
(Hanyang University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Although Type I ELM heat flux mainly reaches the divertor plates, it would cause severe damage to the first wall in advanced tokamaks due to radial convective loss of ELM. Heat loads on the first wall is mostly caused by the fast radial convective propagation of ELM filaments. In this paper, heat fluxes toward the first wall of KSTAR device are investigated as a form of ELM filaments, and they...
Dr
Rajesh Maingi
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Experiments in NSTX demonstrated reproducible operation with inter-discharge lithium evaporation, eliminating the need for inter-discharge helium glow discharge cleaning (HeGDC), improving plasma confinement as well as the duty cycle. To assess the viability of operation without HeGDC and directly compare with inter-discharge lithium evaporation, the inter-discharge HeGDC duration was...
Dr
Suk-Ho Hong
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In this paper, we report the results from a series of experiment using special tungsten block tiles performed in KSTAR on fuel retention inside the gap of castellated blocks of different shapes. Results presented in this paper suggest a comprehensive understanding on deposition procedure inside the gap and would give valuable information on the Be deposition inside the gap of castellated...
Mr
Phani Kumar Domalapally
(Research Centre Rez)
19/10/2016, 14:00
Determination of the likely heat loads which may be expected on the First Wall (FW) of the projected European fusion reactor DEMO is still underway. This uncertainty notwithstanding, the engineering design of the heat sink components must proceed, hence the scientific community is using the so called bottom-up approach to determine the maximum heat flux that the component could sustain given...
Mr
Stephen Manuel Manoah
(Institute for Plasma Research, Gandhinagar, Gujarat-382428, INDIA)
19/10/2016, 14:00
The ITER presents the most demanding challenge to Remote Handling (RH) operation ever in terms of weight, complex geometry, limited space, required accuracy and task quality level. The ITER in-vessel components are to be maintained or replaced remotely since these components will be activated by high energy neutrons. In order to perform the in-vessel RH maintenance tasks, an RH system known as...
Prof.
Göran Ericsson
(Applied Nuclear Physics, Dept of Physics and Astronomy, Uppsala University, Uppsala Sweden)
19/10/2016, 14:00
The proposed High Resolution neutron Spectrometer (HRNS) system for ITER is composed of a suite of neutron spectrometers with the primary function to provide measurements of the fuel ion ratio, nT/nD, in the plasma core. Supplementary functions are to assist or provide information on fuel ion temperature, Ti, energy distributions of fuel ions and confined alpha-particles and neutron emission...
Mr
Carl Hellesen
(Uppsala University)
19/10/2016, 14:00
Measurements of the core plasma fuel ion density ratio (nT/nD) is required for safe and efficient burning plasma operations at ITER. However, this measurement is difficult and very few working techniques have been demonstrated. One candidate method to obtain the fuel ion composition is Neutron Emission Spectroscopy, specifically, measurement and analysis of the DT neutron spectrum of neutral...
Dr
Massimo Nocente
(Department of Physics, ItUMiB)
19/10/2016, 14:00
Among the key goals of ITER are the investigation of alpha particle physics in a burning plasma as well as the demonstration of the control of runaway electrons born in disruptions. The diagnostic needs to meet these goals are the determination of the alpha particle profile with a time resolution of < 0.1 s and the evaluation of the runaway electron beam current and end point energy with an...
Mr
Nikolai Bakharev
(Ioffe Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
For the first time a high energy counter-NBI was applied in the Globus-M spherical tokamak. The ELM-free H-mode was obtained. However no significant increase in the ion temperature and plasma energy content as compared to ELMy H-mode was observed. This is due to a high level of the fast ion losses (up to 97%), confirmed by modeling with NUBEAM and full 3D fast ion tracking algorithm. Increase...
Dr
Elena Belova
(PPPL)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
An energy channeling mechanism is proposed to explain flattening of the electron temperature profiles at high beam power in beam-heated National Spherical Torus Experiment (NSTX). High-frequency Alfvén eigenmodes are frequently observed in beam-heated NSTX plasmas, and have been linked to enhanced thermal electron transport and flattening of the electron temperature profiles. Results of 3D...
Dr
Jinseok Ko
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The current profile evolutions have been measured from the plasma discharges with the electron cyclotron current drive (ECCD) for the Korea Superconducting Tokamak Advanced Research (KSTAR) for the first time. This measurement has been possible by the newly-installed motional Stark effect (MSE) diagnostic system that utilizes the polarized Balmer-alpha emission from the energetic neutral...
Aleksandr Zvonkov
(Project Center ITER)
19/10/2016, 14:00
CXRS diagnostics supply a set of important plasma parameters of fusion plasmas. According to the system requirements, the CXRS diagnostics in ITER should supply plasma velocity (poloidal and toroidal), impurity ion densities and ion temperatures. The ITER CXRS-edge diagnostic system must measure these parameters over the outer half of the plasma radius.
The use of CXRS in ITER encounters...
Mr
Kaiming Feng
(Southwestern Institute of Physics)
19/10/2016, 14:00
The current design of Chinese Heilum-cooled Ceramic Breeder Test Blanket Module (HCCB TBM) with 1×4 configuration scheme, it includes 4 independent breeding sub-modules with 10mm gap (for thermal expansion) between each other along the poloidal direction. Tthese sub-modules are connected with a big back plate containing auxiliary connection pipes for coolant and purge gas, shear keys and...
Dr
Kiyoshi Itami
(Japan Atomic Energy Agency)
19/10/2016, 14:00
Advanced design for Divertor Impurity Monitor (DIM) and IR Thermography (IRTh) is being developed in Japan to contribute to the divertor plasma control and research in ITER through the spectroscopic measurement with high spatial and spectral resolutions and accurate measurement of the target temperature.
DIM spectroscopically (200 nm – 1000 nm) measures two dimensional profiles of the...
Mr
Shrishail B Padasalagi
(ITER-India, Institute For Plasma Research)
19/10/2016, 14:00
The ITER Cryostat, the largest stainless steel vacuum pressure chamber ever built which provides the vacuum confinement to components operating in ITER ranging from 4.5 k to 80 k. Cryostat Design Model was qualified[1] by ITER. As a Safety Important Class system, Design qualification at every change in its development and installation phases is mandatory. The Cryostat system is currently at...
Dr
Koji Takahashi
(Japan Atomic Energy Agency)
19/10/2016, 14:00
The ITER EC equatorial launcher (EL) has been newly designed to achieve an enhanced electron cyclotron current drive performance based on the dedicated calculations. The millimeter(mm)-wave beam design of EL optimized the mm-wave transmission capability and spatially limited beam path such as the mirrors' dimension and the plug mounted Blanket Shield Module openings has implemented poloidal...
Mr
ABHISHEK SARASWAT
(InIPR)
19/10/2016, 14:00
Liquid Lead Lithium (Pb-16Li) is of primary interest as one of the candidate materials for coolant fluid and tritium breeder in liquid metal blanket concepts relevant to fusion power plants. For effective and reliable operation of such high temperature liquid metal coolant systems, monitoring and control of critical process parameters like pressure, level, temperature and flow is essential....
Mr
Naotaka Umeda
(Japan Atomic Energy Agency)
19/10/2016, 14:00
Dc ultra-high voltage insulation technologies in oil, gas and vacuum have been newly developed to fabricate dc 1MV power supply components in the neutral beam (NB) system on ITER. In the ITER NB system, a 1 MV power supply with output pulse duration of 3600 s is required, which is twice higher in the voltage and two orders longer in the pulse than those of the existing NB system in the world....
Dr
Ricardo Farengo
(Comision Nacional de Energia Atomica)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Theoretical calculations and particle simulations are used to show that charge changing processes (i.e. charge exchange) can significantly increase the diffusion of alpha particles in the pedestal-edge-SOL regions. The interaction of the alpha particles with the plasma species, He+ and neutral deuterium (both atomic and molecular) and helium are included. The numerical code calculates the...
Dr
Jayhyun Kim
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
It has been regarded that magnetic perturbation (MP) by non-axisymmetric fields is the most promising technique in controlling edge localized mode (ELM) crashes that are potentially harmful to the lifetime of first wall in reactor scale devices. However, the exact mechanism of MP has not been fully understood in both ELM crash mitigation and suppression. Here, we investigated the...
Mr
Jeongwon Lee
(Seoul National University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
ECH-assisted plasma start-up using trapped particle configuration (TPC) is performed in KSTAR 2015 experiment campaign for feasibility study of TPC in superconducting, conventional tokamaks. It is widely known that ECH can significantly assist the start-up of tokamak plasmas with pre-ionization. The dependency of the quality of the ECH pre-ionization plasma on the magnetic configuration has...
Dr
Shin Kajita
(Nagoya University)
19/10/2016, 14:00
Reflection of light on walls will form parasitic signal on various diagnostics and be a serious issue in ITER. In this study, we show the recent progress in the assessment of the effects of the wall reflections in ITER on visible spectroscopy, Thomson scattering, active spectroscopy, and infrared thermography based on the ray tracing simulation modeling. In this study, it is shown that the...
Mr
Joohwan Hong
(Korea Advanced Institute of Science and Technology)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Experiments were conducted in KSTAR plasmas by injecting a trace amount of Ar gas as a test particle while applying two different actuators: electron cyclotron resonance heating (ECH) and resonant magnetic perturbation (RMP). Effects of ECH was investigated in KSTAR L- and H-mode discharges. For L-mode discharges (I_p = 400 kA, B_t = 2 T), 110 GHz ECH of 350 kW was applied to heating positions...
Mr
ARUN KUMAR CHAKRABORTY
(ITER-India, Institute for Plasma Research, Bhat Gandhinagar – 382428, India)
19/10/2016, 14:00
The Beam Source (BS) for Neutral Beam Injectors consists of two parts: “ion source” and “accelerator system”. For the ITER Diagnostic Neutral Beam (DNB), the ion source is the plasma generator and consists of eight inductively coupled Radio Frequency (RF) plasma drivers. The accelerator system consists of three grids and accelerates the negative ion beam to 100 keV. The three grids: plasma...
Dr
Michael Bongard
(University of Wisconsin-Madison)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Operation in the high confinement (H-mode) regime and mitigation of associated deleterious Edge Localized Mode (ELM) activity are necessary for the success of ITER and future reactors. H-mode studies at near-unity aspect ratio A can offer unique insights into these issues. Edge plasma parameters at low A permit unique measurements of the edge pedestal with high spatiotemporal resolution using...
777.
ELM, Edge Turbulence and Their Interaction in the ELM-crash Suppression Phase under the n=1 RMP
Dr
Jaehyun Lee
(Ulsan National Institute of Science and Technology)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The effect of static n=1 resonant magnetic perturbation (RMP) on edge-localized mode (ELM) and edge turbulence has been investigated using electron cyclotron emission imaging (ECEI) system. The ECEI revealed that filamentary ELM is still present in the edge when the ELM crash is completely suppressed by n=1 RMP. Correlation analysis showed the RMP enhances turbulent fluctuations in the edge...
Dr
Junghee Kim
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Energetic ions generated by auxiliary heating and fusion reactions are able to produce the characteristic Alfvenic activities such as excitation of Alfvén eigenmodes (AE) and high-frequency chirping modes through wave-particle interactions. In KSTAR on-axis neutral beam injection (NBI) is a main supplier of the fast ions, and has two primary roles which are heating and current drive. Beam-ions...
Dr
Yang Ren
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Plasma turbulence is considered one of the main mechanisms for driving anomalous thermal transport in magnetic confinement fusion devices. Based on first-principle model, gradient-driven gyrokinetic simulations have often been used to explain turbulence-driven transport in present fusion devices, and in fact, many present predictive codes are based on the assumption that turbulence is...
Dr
Si-Woo Yoon
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
For the realization of the fusion reactor, solving issues for high beta steady-state operation is one of the essential research topics for the present superconducting tokamaks and in this regard KSTAR has been focusing on maximizing performance and increasing pulse length addressing scientific and technical issues. Typically, previous study on high beta operation has been focusing on advanced...
Dr
Masayuki TOKITANI
(JpNIFS)
19/10/2016, 14:00
It is considered that copper alloy could be used as a divertor cooling tube in not only helical reactor FFHR-d1 but also tokamak DEMO reactor, because of utilizing its high thermal conductivity. This study focused on using an oxide dispersion strengthened copper alloy (ODS-Cu) of GlidCop® (Cu-0.3wt%Al2O3) as the divertor heat sink material of FFHR-d1. This alloy has superior high temperature...
Dr
Mark Boyer
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Spherical torus based designs for fusion nuclear science facilities [1] and pilot plants [2] have little to no room for a central solenoid, and require the plasma current to be generated non-inductively. Recently completed upgrades to NSTX-U will enable the study of non-inductive scenarios, including start-up, ramp-up, and flattop current sustainment. This paper examines active control of such...
Dr
Antonis Sergis
(Imperial College London, CCFE)
19/10/2016, 14:00
HyperVapotrons (HVs) are highly robust and efficient heat exchangers able to transfer high heat fluxes of the order of 10-20MW/m2. They employ the Vapotron effect, a complex two phase heat transfer mechanism, which is strongly linked to the hydrodynamic structures present in the coolant flow inside the devices. HVs are currently used in the Joined European Torus (JET) and the Mega Amp...
Dr
Yuejiang Shi
(Seoul National University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In KSTAR experiments, we found that non-local transport (NLT) is closely connected to the rotation reversal and impurity transport. We demonstrated that NLT can be controlled by ECH, and the intrinsic rotation and impurity dynamics follow the change in NLT. Supersonic molecular beam injection (SMBI) was used to induce the cooling of edge electrons. The cut-off density for NLT can be...
Dr
Pavel Aleynikov
(Max-Planck-Institut für Plasmaphysik)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A consistent description of runaway electron (RE) generation in plasma disruptions remains an open physics issue. The possibility of the formation of high post-disruption RE currents raises safety-related concerns for large tokamaks, such as ITER. Although the avalanche mechanism of RE production is anticipated to be the dominant mechanism in ITER [M.N. Rosenbluth, S.V. Putvinski, Nucl. Fusion...
Dr
Donald Spong
(Oak Ridge National Laboratory)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Instabilities driven by energetic particle (EP) components are of interest to magnetic fusion concepts since they can lead to decreased heating efficiency, high heat fluxes on plasma-facing components, and decreased ignition margins in reactor systems. Since 3D magnetic field perturbations will be present to some extent in all toroidal configurations, the analysis of EP instabilities in 3D...
Prof.
Wenlu Zhang
(CnCASIOP)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The fast electron driven beta induced Alfven eigenmode (e-BAE) has been routinely observed in HL-2A tokamak. We study e-BAE for the first time using global gyrokinetic GTC simulation, where the fast electrons are described by the drift kinetic model. Frequency chirping is observed in nonlinear simulations in the absence of sources and sinks, which provide a new nonlinear paradigm beyond the...
Dr
Choong-Seock Chang
(Princeton Plasma Physics Laboratory and KAIST)
19/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The edge gyrokinetic code XGC1 shows that the divertor heat flux width λq in between ELMs of Type I ELMy H-modes in two representative types of present tokamaks (DIII-D type for conventional aspect ratio and NSTX type for tight aspect ratio) is set mostly by the ion neoclassical orbit spread, which is proportional to 1/Ip, while the blobby turbulent spread plays a minor role. This explains the...
Dr
Hyungho LEE
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Divertor target heat loads in future long pulse, high power tokamak reactors such as ITER or DEMO will impose major operational constraints. Detached divertor operation and suppression or substantial mitigation of Edge Localized Modes (ELMs) will be mandatory. One of the most promising ELM mitigation methods to be applied on ITER is the use of 3D magnetic perturbations (MPs). This technique...
Dr
James Anderson
(General Atomics)
19/10/2016, 14:00
ITER ECH transmission lines have challenging-to-meet transmitted waveguide mode purity requirements, pushing individual subcomponents towards strict manufacturing tolerances. In addition, most ECH components will require active cooling to remove heat generated by microwave losses, even those with very high transmission efficiencies. To meet these two particular challenges, several new...
Dr
Thomas Jenkins
(Tech-X Corporation)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The heating of confined tokamak plasma to fusion-relevant temperatures can cause sputtering of high-Z impurities from plasma-facing components, and such impurities radiatively cool the plasma, especially as transport effects carry them to the reactor core. The sputtering process is believed to be exacerbated by the large electromagnetic fields generated by RF antennas, since these fields...
Dr
Hideya Nakanishi
(National Institute for Fusion Science)
19/10/2016, 14:00
A high-performance data transfer method has been developed for full data replication between ITER and the remote experimentation centre (REC) in Japan for the first time. Fast data transfer technology has been investigated as the crucial activity of REC with F4E, JAEA, NIFS, and NII collaboration. Full replication of ITER data will be expected to provide not only an equivalent research...
Dr
Guoyong Fu
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Energetic particle modes and Alfvénic modes driven by super-Alfvénic beam ions were routinely observed in neutral beam heated plasmas on the National Spherical Torus Experiment (NSTX). These modes can significantly impact beam-ion transport, thus causing beam-ion redistribution and losses. In this paper we report on new self-consistent hybrid simulations of both fishbone instability and TAEs...
Dr
David Smith
(University of Wisconsin-Madison)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Characteristic edge localized mode (ELM) evolution patterns are identified and measured at Alfven timescales with a multi-point beam emission spectroscopy (BES) diagnostic on NSTX/NSTX-U, and parameter regimes corresponding to the characteristic ELM evolution patterns are identified. The linear peeling-ballooning stability boundary expresses an onset condition for ELMs, but ELM saturation...
107.
Improving fast-ion confinement in high-performance discharges by suppressing Alfve´n eigenmodes
Mr
Gerrit J. Kramer
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The performance of steady-state DIII-D discharges is often reduced due to anomalous fast-ion
transport that was observed to correlate with Alfv´en eigenmode (AE) activity. Fast-ion transport
modeling using the kick model [1] shows that the observed mode activity can account for the
observed fast-ion confinement degradation. Therefore, suppressing the AE activity will improve
the plasma...
Dr
Won Ha Ko
(Korea, Republic of)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Significant reduction of H-mode power threshold (P_th) has been identified in KSTAR. Such a favorable finding is attributable to low intrinsic error field [1] and toroidal field ripple[2], which has been corroborated by high pedestal rotation. According to a preliminary comparison, KSTAR has at least 10% lower Pth during L to H-mode transition than DIII-D which have similar size but with...
Dr
Syun'ichi SHIRAIWA
(PSFC, MIT)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A new efficient full wave simulation approach to solve a driven RF waves problem in hot core and edge SOL plasmas self-consistently is presented. Existing RF simulation codes are integrated to reconstruct self-consistent solutions from solutions obtained from each code. The approach allows for treating hot core plasma, SOL plasmas and launcher structure self-consistently, incorporating...
Prof.
Kazuaki Hanada
(Advanced Fusion Research Center, Research Institute for Applied Mechanics, Kyushu University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Hydrogen (H) recycling and wall pumping properties on a dynamic retention dominant wall (metal wall) have been investigated in a medium size spherical tokamak QUEST. The plasma facing wall on QUEST originally made of stainless steel type 316L (SS316L) and partially coated by atmosphere plasma splay tungsten has been already covered with re-deposition layer of 5-100 nm in thickness due to...
Dr
Hiroshi Tanabe
(University of Tokyo)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
We present results of recent studies of merging/reconnection heating during central solenoid (CS)-free plasma startup in the Mega Amp Spherical Tokamak (MAST) which achieved major progress in the last three years through the use of new 32 chord ion Doppler tomography, 130 channel YAG- and 300 channel Ruby-Thomson scattering diagnostics. In addition to the previously achieved ~1keV heating...
Dr
Young-Seok Park
(Columbia University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
H-mode plasma operation in KSTAR reached high normalized beta, beta_N, up to 4.3 with reduced plasma internal inductance, l_i, to near 0.7. This significantly surpassed the computed n = 1 ideal no-wall beta_N limit by a factor of 1.6. The high beta_N above 4 has been achieved in discharges having lowered B_T in the range 0.9-1.3 T with plasma current of 0.35-0.43 MA. The l_i was maintained at...
Dr
Woochang Lee
(UNIST)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In KSTAR L-mode discharges (B_t0 = 3−3.3 T and I_P = 600 kA) heated by ~1.5 MW neutral beam injection (NBI), 200−400 kHz turbulent fluctuations were observed with a multichannel (4 radial and 16 poloidal) microwave imaging reflectometer system [1]. Linear gyrokinetic simulations with GYRO predicted that turbulence is most unstable at k_theta ~ 3 /cm (k_theta rho_s ~ 0.4) and the most unstable...
Dr
Steven Sabbagh
(Columbia University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Neoclassical Toroidal Viscosity (NTV) due to non-ambipolar particle diffusion occurs in tokamaks due to low magnitude (dB/B0 ~10-3) three-dimensional (3D) applied magnetic fields, used for positive purposes including alteration of the plasma rotation profile, Vt, to stabilize MHD modes and for ELM suppression. As ITER and future devices will use 3D fields for these purposes, it is important to...
Dr
Aihui Zhao
(Tsinghua University, China)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The lower hybrid current drive (LHCD) is one of the most effective tools for driving current in present tokamak plasmas. However, for reactor-graded density plasmas, the efficiency of LHCD degrades dramatically. The dependence of LHCD efficiency on isotopic plasma content (hydrogen/deuterium) was studied in experiments. Although according to the linear dispersion theory, the deuterium plasma...
Dr
Eugene Mukhin
(Ioffe Institute)
19/10/2016, 14:00
Measuring electron temperature and density profiles is а high priority task for tokamak diagnostics because the electron component is one of the main channels for the anomalous
power loss and it is strongly sensitive to transient processes in the tokamak plasma. The Core TS in ITER must cover the whole core region r/a < 0.85, R > 6 m with a spatial resolution of 67 mm or better and must be...
Prof.
Yuji Hatano
(Hydrogen Isotope Research Center, University of Toyama)
19/10/2016, 14:00
The goal of the Japan-US joint research project PHENIX (2013–2018) is to understand the feasibility of He-cooled W divertor for DEMO applications. To achieve this goal, the project has three major objectives: (1) to understand heat transfer in a divertor module cooled with high-temperature and high-pressure He gas, (2) to establish database on thermomechanical properties of W materials after...
Prof.
Tünde Fülöp
(Chalmers University of Technology)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Runaway electrons (REs) are a pressing issue for ITER due to their significant potential to cause damage. Improved knowledge of RE formation mechanisms, their dynamics and characteristics, as well as transport or loss processes that may contribute to RE suppression and control, will benefit the fusion community and contribute to a safe
and reliable operation of reactor-scale tokamaks.
In...
Mr
Filippo Scotti
(LLNL)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The response of kinetic plasma profiles to 3D-field triggered edge localized modes (ELMs) and the inter-ELM carbon impurity transport were analyzed in lithium-conditioned H-mode discharges in NSTX. ELM-free lithium-conditioned H-mode discharges were characterized by core accumulation of impurities as a result of near-neoclassical impurity transport, an edge inward pinch and the absence of...
Dr
Alexey Arefiev
(Institute for Fusion Studies, University of Texas at Austin, USA)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
High-performance spherical tokamaks are usually overdense, so regular electron cyclotron emission is blocked. However, electron Bernstein waves, generated at the local cyclotron frequency (and its harmonics) in the core may be observed outside the plasma via a mode conversion process that takes place typically in the plasma edge between an electromagnetic mode and the (electrostatic) electron...
Rory Perkins
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
We propose a new model for the anomalous loss of high-harmonic fast-wave (HHFW) heating power to the scrape-off layer (SOL) of the National Spherical Torus eXperiment (NSTX). A significant fraction, up to 60%, of the coupled HHFW power can be lost along scrape-off layer field lines [1], creating bright spirals of heat deposition on the upper and lower divertor regions [2]. It is important to...
Dr
Italo Ricapito
(Fusion for Energy)
19/10/2016, 14:00
The general objective of the ITER TBM Program is to provide the first experimental data on the performance of the breeding blankets in the integrated fusion nuclear environment. Such data are essential to design and predict the performance of DEMO and future fusion reactors. To achieve this objective, the TBM programme will have to: • test and validate technologies and materials in a fusion...
Dr
Gregorio Vlad
(ENEA, Dipartimento FSN, C.R. Frascati, Italy)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Internal kink instabilities exhibiting fishbone like behaviour have been observed in a variety of experiments where a high energy electron population, generated by strong auxiliary heating and/or current drive systems, was present. Numerical simulations using XHMGC, a hybrid MHD-Gyrokinetic code, has been already applied successfully to analyses of modes driven by energetic electrons. In...
Dr
Masayuki Ono
(PPPL/Princeton University)
19/10/2016, 14:00
Steady-state fusion power plant designs present major divertor technology challenges, including high divertor heat flux both in steady-state and during transients. In addition to these concerns, there are the unresolved technology issues of long term dust accumulation and associated tritium inventory and safety issues. It has been suggested that radiation-based liquid lithium (LL) divertor...
Dr
Mikhail Modestov
(Princeton University/Nordita)
19/10/2016, 14:00
Successful design of liquid metal wall or divertors for nuclear fusion reactors require the understanding of the behavior of liquid metal flows. The Liquid Metal eXperiment (LMX) at PPPL has been designed in a form of a rectangular channel allowing investigation of major issues of heat transfer and magnetic field influence relevant to tokamak divertor operation. We present the numerical...
Dr
Luis F. Delgado-Aparicio
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A simple heating technique has been developed that could provide an actuator to circumvent error-field-induced locked-mode disruptions in tokamak plasmas. New observations of the formation and dynamics of error-field-induced locked-modes at ITER toroidal fields, without fueling and external momentum input have recently been carried out on Alcator C-Mod. Locked-mode excitation is achieved by...
Dr
Sang Gon Lee
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Highly coherent structures associated with an extremely long-lived saturated magnetohydrodynamic (MHD) instability have been observed in KSTAR tokamak under a long-pulse and steady-state operation. As the plasma performance is increased in advanced tokamak regimes, possible deleterious effects of MHD modes become more important, especially for steady-state burning plasmas in the next-step...
Dr
MunSeong Cheon
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Recently it is suggested that the loss of runaway electrons localized in the plasma triggers the plasma disruption by transferring their energy to the first wall generating massive impurities, based on the observation in KSTAR. In order to check the feasibility of the suggestion, localized magnetic perturbation was applied on the plasma edge to remove runaway electron beam from the plasma,...
Prof.
Evgeniy Gusakov
(Ioffe Institute)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A model interpreting generation of the anomalous backscattering signal in the second harmonic X-mode ECRH experiments at TEXTOR as a secondary non-linear process, which accompanies a primary low – threshold parametric decay instability (PDI) leading to excitation of two–upper hybrid (UH)–plasmon trapped in plasma is introduced. The primary absolute PDI enhancing the UH wave fluctuations from...
Mr
Arunkumar Chakraborty
(ITER-India, Institute for Plasma Research, Bhat, Gandhinagar – 382 428, Gujarat, India)
19/10/2016, 14:00
Indian Test Facility (INTF) is designed for “Full characterization of the Diagnostic Neutral Beam (DNB)” for ITER, to unveil the possible challenges in production, neutralization and transportation of neutral beam over the path length of ~20.67m. This facility consist of a vacuum vessel (of volume >180m3) which has been designed and manufactured as per ASME Sec.VIII Div. 1, to house and...
Dr
Kwan Chul Lee
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
An analysis of edge density evolution during the large ELMs on KSTAR is developed by the measurements including two interferometer systems and the Beam Emission Spectroscopy (BES). The vertical Far Infra-Red interferometer (FIRI) data of large ELM crashes for the high power heated plasma showed plasma density increase, which is a contrary tendency to the general plasma density change at the...
Dr
Sang-hee Hahn
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The paper summarizes a series of multi-year experimental activities done under the ITPA MHD stability TG from year 2012 to year 2015. The relevant activity, MDC-18, addresses many axisymmetric control issues needing resolution for ITER, which include 1) fundamental controllability of axisymmetric equilibria and relevant metrics, 2) effect of noise in the principal diagnostics and 3) evaluate...
roberto zanino
(dipartimento energia, politecnico di torino)
19/10/2016, 14:00
Solutions for the steady-state power exhaust problem in future fusion reactors (e.g, DEMO) are not automatically provided by present experiments or even ITER, because the expected heat fluxes, as well as the level of neutron irradiation, will be much higher. Dedicated work packages are being devoted to this problem within EUROfusion and even a dedicated facility (the Divertor Tokamak Test –...
Dr
Hiroshi Idei
(Research Institute for Applied Mechanics, Kyushu University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
By means of dual 8.2 GHz and 28 GHz waves, the over dense 25 kA plasma with central high energetic-electron pressure was non-inductively built up and sustained for 0.4 s by Electron Bernstein Wave Heating (EBWH) effect between 8.2 GHz fundamental and 2nd harmonic Electron Cyclotron (EC) layers. Spontaneous Density Jumps (SDJs) have been clearly observed at a few times in a shot, and the...
Prof.
Hitoshi Tanaka
(Kyoto University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Extremely overdense spherical tokamak plasmas are produced non-inductively with electron Bernstein waves mode-converted via O-X-B scheme. When the fundamental electron cyclotron resonance (ECR) layer is located at the plasma core and the 2nd harmonic ECR layer is near the outboard vessel wall and the upper hybrid resonance layer is located between them, significant density rise is obtained...
Dr
Zhiyong Qiu
(Zhejiang University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Theory of low-frequency zonal structure (LFZS) generation as one mechanism for Alfvén eigenmode (AE) nonlinear saturation is presented, including 1) spontaneous excitation of LFZS by beta-induced AE (BAE) via modulational instability, and 2) effects of energetic particles (EPs) on zonal flow (ZF) generation by Toroidal AE (TAE). It is found that, LFZS can be driven by a finite-amplitude BAE...
Dr
Maxime Lesur
(FrIJR)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Energetic ions in fusion plasmas can excite the Geodesic-Acoustic Mode (GAM), which is a finite-frequency counterpart of zonal flow. Depending on plasma conditions, GAMs can significantly enhance or mitigate transport. Therefore, understanding and controlling their excitation is of great interest. Recent observations on the LHD have revealed a new phenomenon of abrupt excitation of...
Zhihong Lin
(UC Irvine)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In this paper, we report gyrokinetic simulations of nonlinear interactions between beta-induced Alfven eigenmode (BAE) and beta-induced Alfven-acoustic eigenmode (BAAE), low frequency modes that have strong interactions with both thermal and energetic particles. When the ion temperature is comparable to the electron temperature, the unstable BAAE can be excited by realistic energetic particle...
Mr
Jian Bao
(Peking University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In this work, we present a fully nonlinear electromagnetic particle simulation model for RF wave in the toroidal geometry, which has been successfully implemented in the gyrokinetic toroidal code (GTC). In this electromagnetic simulation model, the ion dynamics is described by 6D Vlasov equation and the electron dynamics is described by 5D drift kinetic equation. The ion cyclotron orbit is...
Prof.
Chang-Mo Ryu
(POSTECH)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Toroidicity induced Alfven eigenmodes (TAE) [1-3] can be driven unstable by fast particles from neutral beam heating or fusion reactions and have been observed in different tokamaks [4-5]. We report the observation of TAEs in KSTAR plasmas during the 2013-2015 campaigns by the fast particles produced the neutral beam injection and global gyrokinetic simulations of them by using the GTC and...
Prof.
Liu Chen
(Zhejiang University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Zonal flow (ZF) and zonal current (ZC) in fusion devices are manifestations of ,respectively, electrostatic (ESCC) and magnetostatic (MSCC) convective cells in uniform plasmas. Similarly, kinetic Alfv´en waves (KAW) appear as kinetic Alfv´en eigenmodes (KAE) due to the presence of Alfv´en continuum. Employing this paradigm, we have investigated the spontaneous excitation of CC via modulational...
Dr
Xin Wang
(Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, Garching D-85748, Germany)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Shear-Alfvén modes can be driven unstable by energetic particles (EPs) produced by additional heating or nuclear fusion reactions. Alfvénic fluctuations can, in turn, be derimental to EP confinement and lead large EP losses. Understanding the properties of EP confinement largely depends on the insights into Alfvén mode dynamics, with regard to both the linear stability properties; and the...
Dr
Yasunori Kawano
(Japan Atomic Energy Agency)
19/10/2016, 14:00
The International Tokamak Physics Activity (ITPA) Topical Group (TG) on Diagnostics has been conducting R&D activities to support improved ITER diagnostic performance. Highlights of the Topical Group activity focus on: (1) mitigating degradation of first mirrors in optical systems, development of techniques for removing impurity deposition on mirrors; (2) characterization of in-vessel...
Prof.
Zhe Gao
(Tsinghua University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Generation of plasma toroidal flow without or with low momentum input has been attracted much attention due to the key issue of plasma rotation on MHD stabilization and turbulence regulation. The general momentum equation is reached with a generalized ponderomotive force and then the drive and transport of parallel momentum are discussed in the case of rf injection and/or in the drift-wave...
Eric Fredrickson
(PPPL)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The International Tokamak Experimental Reactor (ITER) will have a large population of non-thermal, energetic ions consisting of fusion generated alphas and beam ions injected for current profile control. Potential redistribution and/or loss of those non-thermal ions is thus of concern as it will modify heating profiles, current profiles, and could lead to unacceptable levels of heating of...
Dr
Larry R. Baylor
(Oak Ridge National Laboratory)
19/10/2016, 14:00
The formation and acceleration of cryogenically solidified pellets of hydrogen isotopes has long been under development for fueling fusion plasmas. Injectors are being designed to provide this capability for fueling ITER with DT pellets injected from the inner wall. In addition to the fueling application, smaller pellets of D2 are to be injected from the outer or inner wall to purposely...
Dr
Akira Ejiri
(Graduate School of Frontier Sciences, The University of Tokyo)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Plasma start-up without a large flux swing central solenoid (CS) is one of critical issues in fusion research. In the TST-2 spherical tokamak (ST), non-inductive start-up by waves in the lower-hybrid frequency range (200 MHz) has been studied using three types of antennas. Presently a capacitively-coupled combline (CCC) antenna is used. The maximum sustained plasma current was increased from...
Mr
Shrishail B Padasalagi
(ITER-India, Institute for Plasma Research)
19/10/2016, 14:00
The ITER cryostat—the largest stainless steel vacuum pressure chamber ever built which provides the vacuum environment for components operating in the range from 4.5 k to 80 k like ITER vacuum vessel and the superconducting magnets. The Cryostat is divided into four section, of which, Base section is most complex because of its web shaped structure sandwiched between two 60mm thick plates with...
Dr
Yuanlai Xie
(Institute of Plasma Physics,Chinese Academy of Sciences)
19/10/2016, 14:00
The neutral beam injection system of EAST (EAST-NBIS) consists of two sets of neutral beam injectors (namely EAST-NBI-1 and EAST-NBI-2). Each of them has two ion sources which can operate independently. The assembly of EAST-NBI-2 accomplished in April 2015 after finishing the assembly of EAST-NBI-1 in 2013. The two injectors attended EAST experiment campaign of 2015 and are attending EAST...
Dr
Yohji Seki
(National Institutes for Quantum and Radiological Science and Technology)
19/10/2016, 14:00
R&Ds for starting operation with a full- tungsten (W) ITER (INB-174) divertor have been enhanced by recommendation of the ITER council since 2011. Japan Atomic Energy Agency (JAEA) as Japanese Domestic Agency (JADA) and the ITER organization (IO) have been actively working on the development and demonstration on the full-W ITER divertor under the framework of the task agreement. JAEA is in...
Dr
Liqun Hu
(Institute of Plasma Physcis, Chinese Academy of Sciences)
19/10/2016, 14:00
Great progress has been made to the design of ITER Radial X-ray Camera (RXC). The structure design is optimized and installation process is studied considering the simplification and easiness of maintenance. Remote handling skills and tools are designed for the system maintenance after being activated. For detector cooling against high environment temperature which can be up to 240℃, a...
Dr
Ryota Imazawa
(Japan Atomic Energy Agency)
19/10/2016, 14:00
PoPola measures both orientation angle (θ) and ellipticity angle (ε) of polarization state of multiple probing far-infrared (FIR) laser beams (wavelength is 119 μm). The change of θ and ε are mainly associated with the Faraday and the Cotton-Mouton effects, respectively, and provide information of electron density, electron temperature and magnetic field. Equilibrium reconstruction of PoPola...
Dr
Ivan Vargas-Blanco
(Costa Rica Institute of Technology)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The low aspect ratio spherical tokamak (ST) MEDUSA (Madison EDUcation Small Aspect.ratio tokamak) is currently being re-commissioned in Costa Rica and was donation to Costa Rica Institute of Tecnology by University of Wisconsin-Madison, USA. The major characteristics of this device are [1]: plasma major radius R_o < 0.14m, plasma minor radius a < 0.10m, plasma vertical elongation 1.2, toroidal...
Dr
Daniel Carralero
(IPP Garching)
19/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Heat and particle transport onto plasma-facing components is a key issue for next generation tokamaks, as it will determine the erosion levels and the heat loads at the main chamber first wall. In the Scrape-off Layer (SOL), this transport is thought to be dominated by the perpendicular convection of filaments. In this work, we present recent experiments which have led to an improved picture...
Dr
zhiquan song
(Institute of Plasma Physics, Chinese Academy of Science,)
19/10/2016, 14:00
This paper presents the research and development (R&D) progress of the ITER Polodial Field (PF) converter for the coil power supply system applied in the ITER project. The PF converter system is composed of 14 PF Converter Units (PFCU), with a total apparent power of 1.2 GVA and a rated dc current of 55 kA. Due to the huge system power, unprecedented short circuit level, high reliability and...
Mr
Dong Hyeon Na
(Seoul National University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
For several years, dedicated experiments have been performed in the KSTAR Ohmic L-mode plasmas to investigate the rotation reversal phenomena and it was finally observed in 2015. We found that the rotation reversal can be related to the rotation gradient change with respect to the electron density or the collisionality in the region rho ~ 0.3-0.6. In KSTAR, its possible mechanism was...
Dr
Abhay Ram
(UsMIT)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In tokamak fusion plasmas, coherent, intermittent, fluctuations in the form of blobs or filaments and incoherent fluctuations due to turbulence are routinely observed in the scrape-off layer. Radio frequency (RF) electromagnetic waves, commonly used for heating the plasma and for providing non-inductive plasma current, are excited by antenna structures placed near the wall of a tokamak. These...
Dr
Fulvio Militello
(Culham Centre for Fusion Energy)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
We review the recent MAST exhaust programme which focused on the interplay between Scrape Off Layer (SOL) profiles and filaments, and on the physics of advanced divertors. MAST experiments demonstrated that the broadening of the SOL density profiles observed at high fuelling can occur in the absence of detachment and independently from ionisation sources and that it is reduced at high Ip. At...
Ms
Flavia Bonelli
(Karlsruhe Institute of Technology)
19/10/2016, 14:00
From both the physical and the technical point of view, the description of gas dynamics in the divertor and vacuum systems in tokamak fusion reactors poses a challenging task because of the wide range of regimes covered by the flow: from continuum and slip regimes in the plasma, to transition and free molecular flow in the sub-divertor region. Nevertheless, over the past few years, significant...
Dr
Joon-Wook Ahn
(Oak Ridge National Laboratory)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Understanding of underlying physics processes that determine non-axisymmetric divertor footprints is crucial for ITER’s long pulse operation scenario in the presence of 3-D fields, as they will cause asymmetric erosion and re-deposition of divertor material. It has been recently found that plasma response plays a key role in the formation of 3-D lobe structure and divertor footprints by the...
Dr
Hao WANG
(National Institute for Fusion Science)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Energetic particle driven geodesic acoustic mode (EGAM) and Global Alfven eigenmode (GAE) in a 3-dimensional Large Helical Device (LHD) equilibrium are investigated using MEGA code. MEGA is a hybrid simulation code for energetic particles interacting with a magnetohydrodynamic (MHD) fluid. It is found that the n=10 harmonics of the 3-dimensional LHD equilibrium bring about the coupling between...
Dr
Ilya Senichenkov
(Peter the Great Saint Petersburg Polytechnic University)
19/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Our current understanding of divertor physics indicates that at least partial detachment will be a necessary condition for operation of future fusion power devices such as ITER, DEMO and beyond. In recent years a divertor operation with complete detachment was achieved in full tungsten ASDEX Upgrade with nitrogen seeding [Potzel et al Nucl. Fusion 54 (2014) 013001, Reimold et al Nucl. Fusion...
Dr
Minwoo Kim
(Ulsan National Institute of Science Technology)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A control of the ELM-crash is required for a stable plasma operation in a fusion reactor if the H-mode is adapted as an operation scenario. In the KSTAR H-mode plasma, a comparative study between 2D ECEI images of ELMs and MHD simulations has been performed in order to study the underlying physics of the ELM necessary for establishing an effective and robust ELM control. As a first step, the...
Dr
Yongkyoon In
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Discharges on the Korea Superconducting Tokamak Advanced Research (KSTAR) device often have suffered from minor and major disruptions by a large growth of the m/n=2/1 MHD instability. It requires 3-D measurement to decipher the underlying physics of the complicated disruption dynamics. The electron cyclotron emission imaging (ECEI) system on KSTAR is used to measure a quasi 3-D electron...
Dr
Sehoon Ko
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Steep pedestal profiles of ion temperature (Ti) and toroidal rotation (VФ) are routinely observed in neutral beam injection(NBI)-heated KSTAR H-mode plasmas[W. H. Ko et al Nucl. Fusion {\bf55} 083013 (2015)]. In this work, we report a result of detailed analysis of pedestal characteristics. By analyzing a set of data with different experimental conditions, we show that Ti and VФ pedestals are...
Mr
HyunYeong Lee
(Seoul National University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
EBW is an effective heating method to generate over dense plasma in low magnetic field devices such as ST. The direct XB MC from LFS injection may be used effectively because the LFS X-mode can be easily transmitted to right hand (RH) polarized slow X wave or mode converted to highly damping Bernstein wave. In addition, it requires no injection angle adjustment and complicated hardware...
Dr
GIANLUIGI SERIANNI
(ItRFX)
19/10/2016, 14:00
The ITER tokamak requires two heating Neutral Beam Injectors (NBIs), based on the neutralisation of 40A of negative hydrogen ions accelerated to 1MeV with a pulse length of one hour. As these simultaneous parameters were never experimentally achieved, in order to optimise source operation and to assess beam properties, a specific test facility (“PRIMA”) was established in Padova, comprising...
Dr
Daniele Marocco
(ENEA C. R. Frascati, Dipartimento FSN, Frascati, Italy)
19/10/2016, 14:00
The paper describes the on-going work performed by a Consortium of European institutes on the design of the ITER Radial Neutron Camera (RNC) within a framework contract placed by Fusion For Energy (F4E), the ITER European Domestic Agency. The RNC will measure the uncollided 14 MeV and 2.5 MeV neutrons from deuterium-tritium (DT) and deuterium-deuterium (DD) fusion reactions through an array of...
Dr
Yi Tan
(Tsinghua University)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Toroidal Alfven eigenmodes (TAEs) during minor disruptions have been identified in the ohmic plasmas of the SUNIST spherical tokamak. The TAE modes are observed in the frequency range of 150 - 400 kHz. The mode structure analysis indicates the existence of both m/n=-3/-1 and -4/-1 harmonics, propagating in the electron diamagnetic direction in the laboratory frame of reference. These TAEs...
Prof.
Ambrogio Fasoli
(CRPP-EPFL)
19/10/2016, 14:00
Major upgrades to the TCV infrastructure are implemented to increase the DEMO relevance of its research. A major component is the creation of an in-vessel divertor chamber of variable closure to contribute to the qualification of alternative divertor concepts, including the demonstration of advantageous plasma exhaust performance, combining detachment with particle control, He compression and...
Dr
Holger Reimerdes
(Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas)
19/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Present research towards a plasma exhaust solution for a fusion power plant aims at validating edge physics models to strengthen the predictive capabilities and improving the operating regime and the divertor configuration. The TCV tokamak is used in particular to investigate to what extent geometric modifications of the configuration can affect the plasma exhaust performance by decreasing the...
Prof.
Jiming Chen
(Southwestern Institute of Physics)
19/10/2016, 14:00
China will manufacture 10% of the ITER FW panels, all in EHF type with heat load up to 4.7MW/m2. A hypervapotron (HVT) cooling channel was applied as heat sink to enhance heat transfer. Small scale mock-ups have been manufactured in China and successfully passed the thermal fatigue test at 4.7 and 5.9MW/m2 for 7500cycles and 1500 cycles, respectively. Explosion bonding is used to make...
Prof.
Abdelaziz Sid
(Batna University 1)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
In the present work, the electronic distribution function for high magnetized hot plasma, taking into account the electron ion collisions, is explicitly calculated. The basic equation in this investigation is the Fokker-Planck equation where some justified approximations for fusion and astrophysical magnetized plasmas are used.. By computing the second moment of the distribution function, we...
Dr
Jong-Gu Kwak
(National Fusion Research Institute)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The importance of neutron emission measurements and modeling at present nuclear fusion device rely on its usage for designing future reactor for shielding as well as the fact that it has the information about the plasma property. Especially a small amount of nuclear heating on SC magnet impacts heavily on safe operation of machine due to tight temperature margin of quenching.
Since the...
Dr
Ferran Albajar
(Fusion for Energy)
19/10/2016, 14:00
The EU gyrotron for the ITER Electron Cyclotron heating system has been developed in coordinated efforts from several EU institutions (organized in the EGYC European Gyrotron Consortium, TED and F4E) and under the supervision of ITER Organization Central Team. The design of the ITER gyrotron is based on the EU expertise in the series production of high power and long pulse gyrotrons for the...
Dr
Taina Kurki-Suonio
(Aalto University)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The new physics introduced by ITER operation, of which there is very little prior experience, is related to the very energetic (3.5 MeV) alpha particles produced in large quantities in fusion reactions. These particles not only constitute a massive energy source inside the plasma, but also present a potential hazard to the material structures that provide the containment of the burning plasma....
Vanni Toigo
(Consorzio RFX)
19/10/2016, 14:00
In order to achieve thermonuclear-relevant plasma parameters in ITER, the auxiliary heating systems have to provide 50 MW, out of which 33 MW by two Neutral Beam Injectors (NBI), each designed to operate at 1MV, 40 A for one hour. The unprecedented parameters and the complexity of the NBI systems have led to recognize the need of a dedicated Test Facility to carry out an international R & D...
Dr
Adam McLean
(Lawrence Livermore National Laboratory)
19/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
A comprehensive experimental campaign at DIII-D has advanced understanding and modeling of the effects of drifts and radiating species in diverted plasma up to ITER-relevant collisionality. Unique diagnostic capabilities are employed to show directly that plasma drifts lead to in/out asymmetries as well as shifts in radial parameter profiles throughout the divertor legs, and are a critical...
264.
Toroidal Electromagnetic Particle-in-Cell Code with Gyro-kinetic Election and Fully-kinetic ion
Mr
Jingbo Lin
(CnUSTC)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Current drive and auxiliary heating is critical for fusion plasmas. A kinetic simulation model has been developed using gyro-kinetic electron and fully-kinetic ion by removing fast gyro motion of electrons using the Lie-transform perturbation theory. A particle-in-cell kinetic code is developed based on this model in general magnetic flux coordinate systems, which is particularly suitable for...
Dr
Nicola Bertelli
(Princeton Plasma Physics Laboratory)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The injection of fast waves (FW) in the ion cyclotron range of frequency (ICRF) is a well-established method of heating and driving current in magnetically confined toroidal plasma and it will play an important role in the ITER experiment. Taking into account self-consistently the interaction of FW with both the minority ion population and fast-ion / neutral beam populations is a crucial...
Dr
Joydeep Ghosh
(Institute for Plasma Research)
19/10/2016, 14:00
It is a well-known fact that small / medium-sized tokamaks have enormously contributed in design and development of large size tokamaks such as ITER for building fusion reactors in terms of physics, engineering and diagnostics. Small / medium-sized tokamaks are very convenient to develop and test new ideas, technologies and materials, which because of the risky nature cannot be done in large...
Prof.
Hyeon Park
(NFRI)
19/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Long standing issue of full vs. partial reconnection model of the sawtooth instability is revisited in Korean Superconducting Tokamak Advanced Research (KSTAR). The measured central safety factor (q(0)) by Motional Stark Effect (MSE) is ~1.0 and this measurement alone cannot validate the sawtooth instability model definitively due to non-trivial off-set error. Study of controlled experiment of...
Dr
David Green
(Oak Ridge National Laboratory)
19/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Linear kinetic solvers are the workhorse tools for predicting the core plasma response to applied radio-frequency (RF) power in magnetically confined fusion devices. These codes are typically frequency-domain spectral, or a combination of spectral and finite-element that require the inversion of a large, dense, or block-dense, ill-conditioned double complex matrix. On the engineering side of...
Dr
Xi Chen
(General Atomics)
19/10/2016, 14:20
In a recent discovery, the Quiescent H-mode (QH-mode) regime in DIII-D has been found to bifurcate into a new state at low torque in double-null shaped plasmas, characterized by increased pedestal height, width and global confinement [1, 2]. This provides an alternate path for achieving high performance ELM-stable operation at low torque, in addition to the conventional QH-mode operation...
Dr
Mike Dunne
(IPP-Garching)
19/10/2016, 15:20
Scrape-off layer (SOL) properties are controlled by a number of parameters, such as heating power, main ion fuelling, and impurity seeding. The high field side high density (HFSHD) is a region of high density (~10× higher than the separatrix density) localised to the HFS SOL and is observed in both ASDEX Upgrade (AUG) and JET when a gas puff at sufficient heating power is applied. It can be...
Dr
Ian Chapman
(CCFE Fusion Association)
19/10/2016, 15:40
The pedestal height has been significantly increased by optimising the plasma conditions at H-mode access in joint experiments in JET, ASDEX Upgrade, MAST and TCV. A predictive pedestal model has been developed negating the need to specify the global β and core density peaking. This model predicted that doubling the core pressure during the L-mode phase in JET would increase the pedestal...
Dr
C. Craig Petty
(General Atomics)
19/10/2016, 16:40
A new regime with beta, collisionality and plasma shape relevant to the ITER steady-state mission has been attained in DIII-D using the fully noninductive hybrid scenario, including complete ELM suppression over a wide q_95 window (between 5.9 and 7.1) and with little confinement degradation using resonant magnetic perturbation (RMP) coils. Furthermore, high-beta hybrid plasmas have been...
Dr
Jinping Qian
(Institute of plasma physics, Chinese academy of sciences)
19/10/2016, 17:00
Extension of large radius internal transport barrier (ITB), high bootstrap current fraction scenario toward low plasma rotation and q95 relevant to steady state operation at Q=5 in ITER has been successfully demonstrated in DIII-D. New DIII-D experiments have shown that the key feature of large radius ITB and excellent energy confinement when the scenario is extended inductively to higher...
Mr
A. M. Garofalo
(General Atomics)
19/10/2016, 17:20
Experiments on EAST [1] have started to adapt the fully-noninductive high poloidal beta scenario developed on DIII-D [2,3], in order to demonstrate, in principle, steady state tokamak operation at high performance on metal walls. The electron density is systematically varied in order to vary the deposition profile of the external lower hybrid current drive (LHCD), while keeping the plasma in...
Dr
Hiromi Takahashi
(National Institute for Fusion Science)
19/10/2016, 17:40
In future reactors, the fusion reaction is expected to be sustained under the electron heating dominant condition, where both ion temperature and electron temperature are high. Thus the characterization of the thermal transport for the plasmas, of which ion temperature and electron temperature are simultaneously high, is necessary. In recent years, an integration of high ion temperature and...
Prof.
Satoru Sakakibara
(National Institute for Fusion Science)
19/10/2016, 18:00
Previous experiments in LHD show that high beta plasma with more than 5% was successfully achieved in the high collisional regime because of low magnetic field operation at 0.425 T. To investigate the collisionallity dependence of plasma confinement property, we have made high beta experiments in relatively high-field configurations at 1 T to increase the electron temperature. As a result,...
Dr
Matthias Hirsch
(Max-Planck-Institut für Plasmaphysik)
19/10/2016, 18:20
Wendelstein 7-X (W7-X) is built to assess the concept of optimized stellarators at reactor-relevant values of both collisionality and the plasma beta.
In its first operation phase (started in the end of 2015 for 10 weeks of plasma experiments), the device is equipped with five uncooled, inboard carbon limiters. This phase of the project is dedicated to integrated operation, commissioning...
Mr
Arturs Zarins
(University of Latvia, Institute of Chemical Physics), Dr
Gunta Kizane
(University of Latvia), Ms
Liga Avotina
(University of Latvia)
20/10/2016, 08:30
In the frame of EUROfusion consortium programme, Institute of Chemical Physics and Faculty of Chemistry of the University of Latvia are performing investigations on plasma facing, neutron multiplying and self-sufficient tritium generating functional materials for the use of International Thermonuclear Experimental Reactor (ITER) and DEMOnstration power plant.
Be is used as plasma facing...
K.W. Hill
(Princeton Plasma Physics Laboratory)
20/10/2016, 08:30
X-ray spectroscopy will be used in indirect drive experiments at the National Ignition Facility (NIF) to diagnose plasma conditions and mix in ignition capsules near stagnation times, thus indicating the quality of the implosion, and at various positions in the hohlraum. The electron temperature, Te, and density, ne, will be measured from dielectronic satellites and Stark broadening,...
Dr
Ulrich Fischer
(Karlsruhe Institute of Technology (KIT))
20/10/2016, 08:30
Neutronics simulations play an important role for the design and optimisation of the nuclear components of a fusion reactor and the related performance analyses. Accurate data need to be provided to predict the Tritium breeding capability, assess the shielding efficiency, estimate the nuclear power generated in all components, and produce activation and radiation damage data for the irradiated...
Dr
Amanda Hubbard
(Massachusetts Institute of Technology, Plasma Science and Fusion Center)
20/10/2016, 08:30
Significant progress has been made on Alcator C-Mod in expanding the configurations and conditions for which the I-mode regime can be accessed and maintained and understanding the physics which underlies the transport improvement. An important result from multidevice studies is that the power threshold for I-mode has only a weak dependence on BT, while the upper power limit increases with BT,...
Dr
Jinping Qian
(Institute of plasma physics, Chinese academy of sciences)
20/10/2016, 08:30
Extension of large radius internal transport barrier (ITB), high bootstrap current fraction scenario toward low plasma rotation and q95 relevant to steady state operation at Q=5 in ITER has been successfully demonstrated in DIII-D. New DIII-D experiments have shown that the key feature of large radius ITB and excellent energy confinement when the scenario is extended inductively to higher...
Dr
C. Craig Petty
(General Atomics)
20/10/2016, 08:30
A new regime with beta, collisionality and plasma shape relevant to the ITER steady-state mission has been attained in DIII-D using the fully noninductive hybrid scenario, including complete ELM suppression over a wide q_95 window (between 5.9 and 7.1) and with little confinement degradation using resonant magnetic perturbation (RMP) coils. Furthermore, high-beta hybrid plasmas have been...
Dr
Jay Anderson
(University of Wisconsin)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The existence of a magnetic-island induced gap in the shear Alfvén continuum was predicted numerically [Biancalani et al. PRL 2010], but only recently have experimental observations of the MIAE been made in stellarator[Sun et al. PPCF 2015] and RFP plasmas [Cook et al. submitted PPCF 2016]. As the role of 3D magnetic fields in tokamaks grows in prominence, associated changes in the Alfvénic...
Dr
Dmitry Moseev
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
W7-X is an optimized stellarator with n=5 toroidal symmetry. It is designed to produce high performance steady-state plasmas. The main heating mechanism is ECRH, which is capable of delivering continuously up to 5 MW with six gyrotrons at 140 GHz and in the next campaign the total power of the ECRH set-up will be increased to 9 MW and 10 gyrotrons. Such a powerful source of microwaves can also...
Dr
Motoki Nakajima
(Japan atomic energy agency)
20/10/2016, 08:30
Water cooled ceramic breeder concept is a primary candidates for ITER and DEMO blankets of Japan. In this blanket, the pressurized water of 15 MPa between 558 K to 598 K is used as the coolant. In such blanket, the structural material is required to be as thin as possible for tritium breeding. However, the pressure tightness is required to withstand 15 MPa of internal pressure. Therefore one...
Dr
Atsushi Ito
(National Institute for Fusion Science)
20/10/2016, 08:30
To achieve the fuel balance and recycling in ITER and DEMO reactors, it is necessary to understand hydrogen behaviour in plasma facing materials. Because the plasma-wall interaction is determined by particle balance between the flux of plasma particles and the diffusivity in materials, the reproduction of realistic flux and fluence corresponding to experiments is a key issue in simulation. In...
Dr
Xi Chen
(General Atomics)
20/10/2016, 08:30
In a recent discovery, the Quiescent H-mode (QH-mode) regime in DIII-D has been found to bifurcate into a new state at low torque in double-null shaped plasmas, characterized by increased pedestal height, width and global confinement [1, 2]. This provides an alternate path for achieving high performance ELM-stable operation at low torque, in addition to the conventional QH-mode operation...
Prof.
Hong Jin Kong
(KAIST)
20/10/2016, 08:30
Laser fusion drivers requires around 40 kJ@10 ps laser for fast ignition. However, it is hard to produce such a high energy, high repetition rate laser because of the thermal problems. The output energy of current high repetition rate laser projects is at most 100 J, even with using the most advanced laser technologies. A coherent beam combining is one of the most promising technique to...
Mr
Hideo Nagatomo
(Osaka University)
20/10/2016, 08:30
Compression and heating of solid spherical target under the strong external magnetic field is studied using fast ignition integrated interconnecting simulation system (FI^3). The simulation results show that (i) a compression of a solid sphere target is stable, and it is possible to achieve a high areal density core plasma. Using GXII scale laser, it will be 60-80 mg/cm^2. (ii) The magnetic...
Prof.
Takayoshi Norimatsu
(Institute of Laser Engineering, Osaka University)
20/10/2016, 08:30
In this work, we report a conceptual design of a laser fusion experimental reactor (LIFT) and an issue analysis of the design. After the demonstration of ignition and burn by a single shot in fast ignition experiment, construction of an experimental reactor will start. In order to bridge the technological gap between the single-shot experiment and a commercial reactor, an experimental reactor...
Dr
Matthias Hirsch
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 08:30
Wendelstein 7-X (W7-X) is built to assess the concept of optimized stellarators at reactor-relevant values of both collisionality and the plasma beta.
In its first operation phase (started in the end of 2015 for 10 weeks of plasma experiments), the device is equipped with five uncooled, inboard carbon limiters. This phase of the project is dedicated to integrated operation, commissioning and...
Mr
Alexey Razdobarin
(Ioffe Institute)
20/10/2016, 08:30
According to recent experiments in plasma fusion machines, the contamination of optical elements under deposition-dominated conditions in ITER will result in fast degradation of their optical characteristics. The development of deposition-mitigation techniques is an important part of R&D program of ITER optical diagnostics. The presentation is focused on the approaches to be used for the...
Mr
Stephen M. Manoah
(Institute for Plasma Research)
20/10/2016, 08:30
SST-2 is under design as an intermediate step before the Indian demo. The design provides a low fusion gain (Q=5) for realizing the reactor technologies and serve as the test bed for qualifying reactor components and D-T fuel cycle. The design is based on RCC-MR code. The Vacuum Vessel (VV) will be constructed out of SS316LN with control over cobalt content (in the range of 0.03%). The design...
Prof.
Xiang Liu
(Southwestern Institute of Physics)
20/10/2016, 08:30
HL-2M is a new tokamak machine under construction and advanced divertor configuration is one of the major targets. Snowflake and tripod divertor configurations can be performed with up to 3 MA plasma current and 25 MW heating power. The maximal wall load on divertor target plates will reach to 3-7 MW/m2, depending on standard or advanced divertor configurations. Carbon fiber enhanced carbon...
Prof.
JIE YU
(Institute of Nuclear Energy Safety Tech. , CAS)
20/10/2016, 08:30
China has long been active in pushing forward the fusion energy development to the demonstration of electricity generation. Two experts’ meetings were organized in 2014 by Ministry of Science and Technology (MOST) to seriously discuss the China’s fusion roadmap in particular the design and construction of magnetic confinement fusion reactor beyond ITER.
As one of the most challenging...
Brandon Sorbom
(MIT Plasma Science and Fusion Center)
20/10/2016, 08:30
The recent commercialization of high temperature superconductors (HTS) has opened up a new parameter space for the design of tokamak fusion pilot plants. The lack of significant critical current degradation at high magnetic fields of HTS allows tokamaks to be designed with much higher on-axis fields. The ARC reactor design study showed that the use of HTS to design a compact, high-field pilot...
Dr
Alexander Spitsyn
(NRC "Kurchatov institute"), Mr
Dmitry Cherkez
(Ilyich), Mr
Nikolay Bobyr
(NRC "Kurchatov institute")
20/10/2016, 08:30
In the next step fusion devices, such as DEMO or fusion neutron sources high neutron fluxes and fluences are expected. In this case reduce activated (RA) and heat-resistant structural materials should be used.
In Russia V-(4÷10) Ti-(4÷10) Cr alloys, austenitic and RA ferritic-martensitic steels for fission applications are developed and manufactured in A.A. Bochvar High-technology Research...
Dr
Juergen Rapp
(Oak Ridge National Laboratory)
20/10/2016, 08:30
Linear plasma generators are cost effective facilities to simulate divertor plasma conditions of present and future fusion reactors. They are used to address important R&D gaps in the science of plasma material interactions and towards viable plasma facing components for fusion reactors.
Next generation plasma generators have to be able to access the plasma conditions expected on the divertor...
Mr
Takuya Nagasaka
(National Institute for Fusion Science)
20/10/2016, 08:30
Reduced-activation ferritic steels and their oxide-dispersion-strengthened (ODS) alloys are promising structural material for fusion blanket. The ODS steels are superior to the non-ODS steels in heat resistance and neutron irradiation resistance, however inferior in mass production. Since high temperature and high neutron dose area is limited at only the first wall section of the blanket,...
Mr
A. M. Garofalo
(General Atomics)
20/10/2016, 08:30
Experiments on EAST [1] have started to adapt the fully-noninductive high poloidal beta scenario developed on DIII-D [2,3], in order to demonstrate, in principle, steady state tokamak operation at high performance on metal walls. The electron density is systematically varied in order to vary the deposition profile of the external lower hybrid current drive (LHCD), while keeping the plasma in...
Prof.
Yunfeng Liang
(Forschungszentrum Jülich GmbH, Germany)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Plasma–wall interaction (PWI) in the divertor region of Wendelstein 7-X (W7-X) will be of great importance for operational phase OP1.2. While the erosion of the divertor will have an impact on its lifetime and is therefore a critical subject of investigation, fundamental PWI studies in the divertor region are in many ways equally significant. These plasma–wall interactions will be influenced...
Dr
Yasuhisa Oya
(Shizuoka University)
20/10/2016, 08:30
Elucidation of tritium dynamics is one of the key issues for sustainable D-T fusion. Tungsten will be exposed to high fluxes of tritium (T) accompanied with various energetic particles. Therefore, T retention and its trapping states will be dramatically changed by the accumulation of ion and neutron-induced damage and recovery by heating. These facts motivate us to perform extensive hydrogen...
Lorenzo Frassinetti
(KTH, Royal Institute of Technology)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The plasma braking due to resonant and non-resonant magnetic perturbations (MPs) is experimentally studied in the EXTRAP T2R [1] reversed-field pinch (RFP) and the results compared with theoretical models adapted to the RFP configuration.
The resonant MP produces the tearing mode (TM) braking and, eventually, when the MP amplitude is above the locking threshold, the TM locking. The unlocking...
Dr
Yuji Nobuta
(Hokkaido Univ.)
20/10/2016, 08:30
In the present study, long-term samples made of stainless steel, which is the same material as the first wall panels in the LHD, were mounted at a lot of places on the plasma-facing surface in the LHD during the 17th experimental campaign (FY2013) and the surface modifications caused by plasma-surface interactions were evaluated. In addition, in order to investigate hydrogen isotopes release...
Prof.
Daniel Den Hartog
(UsUWisMad)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Over the past several decades, numerical simulation has successfully described various dynamical phenomena in fusion research plasmas. Substantial effort is now being applied to enhance the quantitative predictive capability of numerical simulation. Two key tools for this effort are quantitative validation and integrated data analysis (IDA). To perform validation, results of a numerical...
Dr
Sergey Bozhenkov
(Max-Planck Insitute for Plasma Physics)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
In the first Wendelstein 7-X operational campaign a dedicated limiter configuration was used for both helium and hydrogen plasmas. The achievable discharge duration and the heating power depend on the symmetry of power distribution between five limiters. Toroidally asymmetric loads appear due to misalignments and intrinsic error fields. It is found numerically that for misalignments of a few...
Dr
Samuel Lazerson
(Princeton Plasma Physics Laboratory)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The measurement and correction of error fields in Wendelstein 7-X (W7-X) is critical to long pulse high beta operation, as small error fields may cause overloading of divertor plates. Accordingly, as part of a broad collaborative effort, the detection and correction of error fields on the W7-X experiment has been performed using the U.S. supplied trim coil system [1] in conjunction with the...
Dr
Alberto Loarte
(ITER Organization)
20/10/2016, 08:30
In order to evaluate if W accumulation is expected in ITER plasma conditions and whether the available heating systems can provide the degree of control required for stable H-mode operation we have applied integrated plasma models (ASTRA and JINTRAC) to a wide range of plasma conditions in ITER including confinement transients (i.e. L-H and H-L transitions). The studies find that, in agreement...
Dr
David Brower
(UCLA)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Drift wave turbulence underlies key transport phenomena in toroidal, magnetically confined plasmas. While long-studied for the tokamak and stellarator configurations, the distinguishing features of the reversed field pinch (RFP) allow further development of gyrokinetic models that build on the RFP’s features of high-beta, large magnetic shear (tending to add stability), and relatively weak...
Prof.
George TYNAN
(University of California San Diego)
20/10/2016, 08:30
We present plasma-implanted D retention and thermo-mechanical properties in ion-beam displacement damaged tungsten targets. Cu ion beams with energies ranging from 0.5-5 MeV induce displacement damage of up to 1 displacement per atom (dpa) in the first micron of the surface in W samples held at a controlled temperature. Damaged samples are then exposed to D plasmas at 300-400 K to decorate...
Dr
Maria Ester Puiatti
(Consorzio RFX)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
RFX-mod is a flexible device capable of operating both as a Reversed Field Pinch and as a Tokamak, both circular and shaped. In both configurations the explored parameter range and the effectiveness in dealing with critical issues for magnetic confinement will be extended by some enhancements aiming at: a) reducing magnetic chaos by improving the performance of MHD control system; b) improving...
Prof.
Satoru Sakakibara
(National Institute for Fusion Science)
20/10/2016, 08:30
Previous experiments in LHD show that high beta plasma with more than 5% was successfully achieved in the high collisional regime because of low magnetic field operation at 0.425 T. To investigate the collisionallity dependence of plasma confinement property, we have made high beta experiments in relatively high-field configurations at 1 T to increase the electron temperature. As a result,...
Dr
Hiromi Takahashi
(National Institute for Fusion Science)
20/10/2016, 08:30
In future reactors, the fusion reaction is expected to be sustained under the electron heating dominant condition, where both ion temperature and electron temperature are high. Thus the characterization of the thermal transport for the plasmas, of which ion temperature and electron temperature are simultaneously high, is necessary. In recent years, an integration of high ion temperature and...
Prof.
Yoshitaka Mori
(The Graduate School for the Creation of New Photonics Industries)
20/10/2016, 08:30
Fast heating is a scheme to heat an imploded high density plasma into a hot state before the plasma hydro dynamically expands and dissolves. For a heating process driven by laser induced hot electron currents, the energy of hot electrons beyond MeV having a range of a few g/cm^2, therefore collisional coupling is inefficient until the core density reaches hundreds g/cc. To improve the MeV...
Dr
Stefan Marsen
(Max-Planck-Institut für Plasmaphysik Teilinstitut Greifswald)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
W7-X is a steady state capable optimized stellarator. The main heating system is electron cyclotron resonance heating (ECRH) operating at 140GHz providing up to 9MW microwave power.
A set of diagnostics has been developed to protect the machine from non absorbed ECRH power which can easily damage in vessel components.
The power is launched into the machine by front steerable quasi-optical...
Prof.
Sümer Şahin
(ATILIM University)
20/10/2016, 08:30
The structural material should have the properties given briefly as below:
• Low neutron absorption cross sections.
• Adequate mechanical properties before and after irradiation.
• Operation at a wide temperature window.
• Working at high temperatures.
• Resistant to atomic displacement and helium generation damage.
• Low activation property under 14 MeV neutrons.
• High thermal...
Dr
Alexey Zhirkin
(NRC “Kurchatov Institute”)
20/10/2016, 08:30
In this report the requirements to the calculation accuracy of the main parameters of the fusion neutron source and the thermonuclear blankets with the DT fusion power of more than 10 MW are formulated. To conduct the benchmark experiments the technical documentation and calculation models were developed for two blanket micro-models: the molten salt and heavy water solid-state blanket. The...
Dr
Monica Spolaore
(Consorzio RFX, Padova, Italy)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The RFX-mod experiment is a fusion device designed to operate as a Reversed Field Pinch (RFP), with a major radius R= 2 m and a minor radius a = 0.459 m. Its high versatility recently allowed operating also as an ohmic tokamak allowing comparative studies between the two configurations in the same device. The device is equipped with a state of the art MHD mode feedback control system,...
Dr
Michael Jaworski
(Princeton Plasma Physics Laboratory)
20/10/2016, 08:30
M.A. Jaworski1,a, A. Brooks1, P. Rindt2, K. Tresemer1, J.-P. Allain3, R.J. Goldston1, T.K. Gray4, R. Kaita1,
N. Lopes-Cardozo2, J. Nichols1, J. Menard1, M. Ono1, D.N. Ruzic3, J. Schwartz1, and the NSTX-U Team
1Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA
2Technological University of Eindhoven, Eindhoven, The Netherlands
3Department of Nuclear, Plasma and Radiological...
Prof.
Mizuki Sakamoto
(Plasma Research Center, JpUTsukuba)
20/10/2016, 08:30
Tungsten is a candidate material for plasma facing components of DEMO as well as divertor plates of ITER, because it has favorable properties such as a very low solubility for hydrogen isotopes. However, surface condition of the plasma facing material is certainly changed by plasma-wall interaction (PWI). Such a surface modification could affect a property of H isotope retention which is a key...
Mr
Kevin Woller
(Massachusetts Institute of Technology)
20/10/2016, 08:30
Helium (He) ion energy modulation is demonstrated, for the first time, to affect the development of the tungsten (W) nano-tendril morphology that results from He irradiation. Dramatically isolated nano-tendril bundles (NTBs) grow from the surface instead of a uniform nano-tendril layer, or so called fuzz, leaving ~90% of the surface without nano-tendril growth at all. The growth parameters for...
Prof.
Sadao Masamune
(Kyoto Institute of Technology)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
We have modified the active MHD control system in RELAX in order to compensate for the sideband effect arising from two poloidal gaps of the vacuum vessel. As a result, the discharge duration has reached iron-core-saturation-limited level with stabilization of the resistive wall mode (RWM). The plasma performance has also been improved; the central electron poloidal beta, the ratio of central...
Dr
Yasunobu Arikawa
(Insituteof Laser Engineering Osaka University)
20/10/2016, 08:30
In the fast ignition scheme, a fusion fuel is compressed by implosion laser and then heating laser heats the core plasma to ignition temperature. The heating laser interacts with the cone target and fast electrons are accelerated, and the electrons are absorbed by the core plasma so that the core plasma is heated to ignition temperature. Since LFEX (heating laser) energy is limited to 10 kJ at...
Dr
Rajabbay Khaydarov
(IAPh)
20/10/2016, 08:30
In recent years the ion components of the laser-produced plasmas has been intensively studied as an object to provide high-density and high-energy ion sources, which can be effectively used in the field of inertial confinement fusion. It is well known that processes taking place during the interaction of laser radiation with solid targets strongly depend on the target material leading to...
Prof.
Tao Lan
(University of Science and Technology of China)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Keda Torus eXperiment (KTX) is a medium size reversed field pinch (RFP) machine which has been constructed to study active feedback control of MHD modes, electromagnetic turbulences and plasma wall interaction under different magnetic configurations, such as low safety factor (q) tokamak and reversed field pinch. The variation of magnetic topology in the presence of both external and internal...
Dr
Novimir Pablant
(Princeton Plasma Physics Laboratory)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The performance of the Wendelstein 7-X (W7-X) stellarator during the first experimental campaign (OP1.1) is explored using measurements from the x-ray imaging crystal spectrometer (XICS) diagnostic. During OP1.1 plasmas have been produced in a limiter configuration, with up to 4 MW of ECH power. The properties of both helium and hydrogen plasmas are investigated.
The XICS system is...
Dr
Toshihiko Shimizu
(Institute of Laser Engineering, Osaka University)
20/10/2016, 08:30
Investigating the fusion plasma is necessary to control the fusion process and to understand the plasma dynamics. Down-scattered (DS) neutrons detection is much suitable for measurement of the areal-density. We have demonstrated that lanthanide-doped 20Al(PO3)3-80LiF (APLF) has excellent characteristics as DS neutron scintillators. In this paper, the properties of lanthanide-doped APLF...
Dr
Andreas Krämer-Flecken
(DeFJ)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
For the first operation phase of the optimized stellarator W7-X, a heterodyn poloidal correlation reflectometry (PCR) diagnostic is installed and in operation. The PCR system consists
of an antennae array with one launching and four receiving antennae. The system is operated in a frequency range 22 GHz to 40 GHz. With the selected O-mode polarization of the system a density range of 0.6 ×...
Dr
Narguess Nemati
(Nuclear Science and Technology Research Institute (NSTR), Plasma Physics and Nuclear Fusion Research School, A.E.O.I., Tehran 14155-1339, Iran)
20/10/2016, 08:30
10-layered (100 wt.% W- 90 wt. %W/10 wt. %Cu- 80wt. %W/2wt.%0Cu….100wt.%Cu) W/Cu functionally graded material (FGM) with dispersion of Al13Fe4 CMA particles was synthesized by powder metallurgy technique at different temperatures for 1 hour under a load of 650 MPa. The influences of different sintering processes on relative density, hardness, neutron irradiation resistance and microstructure...
Dr
Kunihiro Ogawa
(National Institute for Fusion Science)
20/10/2016, 08:30
High-temperature and high-density plasmas are achieved by means of real time control, fast diagnostic, and high power heating systems. Those systems are precisely controlled by means of transmission and highly integrated electronic components. However, the radiation damage due to neutron and gamma-ray may lead to serious impact on those systems. Therefore, effects due to irradiation on...
Prof.
Masayoshi Nagata
(University of Hyogo)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Transient Coaxial helicity injection (T-CHI) has been examined in the Helicity Injected Spherical Torus (HIST) device for solenoid-free plasma startup in a ST. Here, we report the formation process of T-CHI start-up plasma including flux-surface closure and fast magnetic reconnection. Experimental observation shows that (i) two or three plasmoids or islands are generated in elongated toroidal...
Prof.
Rajdeep Singh Rawat
(National Institure of Education, Nanyang Technological University, Singapore-637616)
20/10/2016, 08:30
For the purpose of investigating the damage processes of surface layers during transient heat loads, fuel retention and dust issues of tungsten as candidate plasma facing materials, the International Atomic Energy Agency (IAEA) organized a dedicated Coordinated Research Project (CRP F1.30.13) from 2011-2015. The CRP involved 18 institutions from 15 member states. The activities concentrated on...
Dr
Ian Chapman
(CCFE Fusion Association)
20/10/2016, 08:30
The pedestal height has been significantly increased by optimising the plasma conditions at H-mode access in joint experiments in JET, ASDEX Upgrade, MAST and TCV. A predictive pedestal model has been developed negating the need to specify the global β and core density peaking. This model predicted that doubling the core pressure during the L-mode phase in JET would increase the pedestal...
Dr
Matteo Agostini
(Consorzio RFX)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Three-dimensional magnetic fields are commonly applied to the plasma edge of fusion devices in order to modify the plasma wall interaction, edge-localized modes (ELM) frequency, divertor loads and transport. However, the action of these magnetic perturbations (MPs) on the edge plasma is still not well understood, and to date there is no obvious relationship between the edge pressure gradient...
Dr
Glen Wurden
(LANL)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
During the first operational phase (OP1.1) of the new W7-X stellarator, five poloidal graphite limiters serve as the main boundary for the plasma. For one of the limiters (Module 3) we have a common sight line for high resolution fast visible and mid-band infrared cameras, as well as filtered photomultipliers. Another limiter (Module 5) is instrumented with tangential view visible and near and...
Dr
Subrata Pradhan
(Institute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat, India)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Runaway dominated low density discharges are modeled for SST-1 using the model as proposed by I El Chamaa Neto et al. [2] for before Plasma Facing component installation and after Plasma Facing component installation. For both the cases modeled results are compared with the measured data. It is found that the runaway generation takes place in the outer region of the Plasma column and the...
Dr
Marius Wirtz
(Forschungszentrum Jülich)
20/10/2016, 08:30
Plasma facing materials (PFMs) for future fusion devices like ITER have to withstand severe environmental conditions such as steady state and transient thermal loads as well as high particle (H, He, n) fluxes. The design and the performance of plasma facing components (PFCs) such as the divertor targets strongly depend on the selection of suitable PFMs, e.g. refractory metals, which meet...
Mr
Philipp Drews
(Forschungszentrum Jülich GmbH,Germany)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Wendelstein 7-X (W7-X), one of the world’s largest stellarators, located at the IPP Greifswald, started operation recently with a limiter configuration. Edge plasma profile measurements, especially those of the electron temperature and density, will play a key role in validating the performance in comparison to the tokamak and hence the viability of a stellarator fusion reactor. The first...
Mr
JASRAJ DHONGDE
(Institute for Plasma Research)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Steady State Superconducting Tokamak (SST-1) is a medium size Tokamak (R/a=1.1/0.2, BT ~1.5T to 3T, IP ~ 102kA) in operation at the Institute for Plasma Research, India. SST-1 has been consistently producing plasma currents in excess of 100kA, with Plasma durations above 250ms and a central magnetic field of 1.5T in recent experimental campaigns of 2016. Investigation of experimental data...
Dr
Andreas Langenberg
(Max-Planck-Institut für Plasmaphysik,17491 Greifswald, Germany)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Starting from the first operation of the Wendelstein 7-X (W7-X) stellarator, the x-ray imaging crystal spectrometer system (XICS) routinely provides line of sight integrated measurements of electron, Te, and ion temperatures, Ti, as well as Ar impurity densities, nAr, based on the spectral emission of an argon tracer impurity. In addition, XICS is capable to measure plasma flow velocities v...
Dr
Heun Tae Lee
(Osaka University)
20/10/2016, 08:30
To date, the primary method for fuel retention estimates in next step devices has been based on projection of laboratory data with input from gas balance and post-mortem analysis. The use of a large database minimizes risk, but the static nature of the retention data is not amendable to making projections under varied conditions. One recent example would be the failure of predicting how the...
Prof.
Jose Manuel Perlado
(Instituto Fusion Nuclear / UNIVERSIDAD POLITECNICA MADRID)
20/10/2016, 08:30
Multiscale Modeling (MM) demonstrates its important role in the deep understanding of physics mechanisms involved in materials behavior under extreme conditions. Damage of materials by neutrons and ion irradiation in Fusion Systems is progressively better characterized by using a combination of experiments and simulation. It is also possible to give the conditions of Hydrogen (EOS) when...
Dr
Satoshi SATO
(Japan Atomic Energy Agency)
20/10/2016, 08:30
In order to validate the nuclear data, we performed integral experiments on tungsten, vanadium-alloy (V-4Cr-4Ti) and copper with the DT neutron source at JAEA/FNS over 20 years ago. The calculated results largely underestimated the measured ones sensitive to low energy neutrons. Background neutrons scattered in the concrete wall of the experimental room may cause these underestimations. In...
Prof.
Igor Garkusha
(IPP NSC KIPT)
20/10/2016, 08:30
Understanding of plasma-surface interaction (PSI) effects during the transient events (disruptions, VDEs, ELMs) in tokamak reactor requires dedicated R&D activity in plasma simulators used in close connection with material characterization facilities as well as with theory and modeling activities. For such investigations different simulators of transient loads are now involved (quasistationary...
Dr
Santanu Banerjee
(Institute for Plasma Research)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Study of the plasma dynamics during the termination phase of a tokamak discharge, particularly during a major disruption, is extremely important for gaining an understanding of essential processes that impact operation limits (e.g. the β limit), outward heat and particle flux and plasma control. Behavior of the edge and scrape off layer plasma during such an event is also vital since this...
Mr
JASRAJ DHONGDE
(Institute for Plasma Research)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Steady State Superconducting Tokamak (SST-1) is a medium size operational Tokamak (major radius=1.1m, minor radius=0.2m) at the Institute for Plasma Research (IPR), India [1]. In the recent experimental campaign, SST-1 has successfully achieved plasma current in order of 100kA and plasma duration in excess of ~330ms at a central magnetic field of 1.5T. An attempt has made to observe/study the...
Dr
Sergey Rogozhkin
(SSC RF ITEP of NRC “Kurchatov Institute”)
20/10/2016, 08:30
Oxide dispersion strengthened steels providing exceptional high-temperature creep and irradiation resistance are presently being developed for fusion reactor. Excellent mechanical properties of ODS steels are directly related to the high density of homogeneously distributed, well-formed oxide particles (such as Y2O3, or Y-Ti-O). However, atom probe tomography (APT) study of ODS steels revealed...
Dr
Iole Palermo
(CIEMAT, Fusion Technology Division, Avda. Complutense 40, 28040-Madrid, SPAIN)
20/10/2016, 08:30
The neutronic radiation coming from the fusion plasma of large machines as the foreseen DEMO could severely affect the stability and the lifetime of the components which constitute the reactor. Nevertheless neutrons are fundamental to allow the reactor to reach the tritium self-sufficiency and to generate and extract enough nuclear power. This means that in the nuclear design of a kind of...
Prof.
Takaaki Fujita
(Nagoya University)
20/10/2016, 08:30
The fast neutrons produced by DT fusion are able to burn the long-lived biologically hazardous transuranics (TRUs) in the spent fuel discharged from fission light water reactors more efficiently than other sources like fast fission reactors. Although a concept design of such a system employing a conventional tokamak (like ITER) with super-conducting coils as the fusion core was proposed, the...
Prof.
Wandong Liu
(University of Science and Technology of China)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The Keda Torus eXperiment (KTX) is a new reversed field pinch (RFP) device at the University of Science and Technology of China. KTX is complementary to the existing international Revered Field Pinch (RFP) facilities. KTX includes the vacuum chamber, conducting shell, magnetic field windings, power supply, active control coils, vacuum pump, wall baking and data acquisition system, KTX...
Dr
Arkadi Kreter
(Forschungszentrum Juelich)
20/10/2016, 08:30
The fuel retention and the lifetime of plasma-facing components are critical plasma-material interaction factors potentially limiting the availability of a magnetic fusion reactor. Linear plasma devices are excellent test beds for investigating specific questions of plasma-material interaction. This contribution summarizes the recent plasma-material interaction studies on the linear plasma...
Mrs
Sylvie Jacquemot
(LULI)
20/10/2016, 08:30
The EUROfusion ToIFE project, launched in 2014 and gathering 14 European laboratories from 9 different countries, aims at achieving the fundamental understanding required to demonstrate the viability of laser-driven fusion as an alternative road towards sustainable, clean and secure energy source. It hinges on (i) a program of experiments and numerical simulations to understand underlying...
Dr
Jozef ONGENA
(Laboratory for Plasma Physics, Ecole Royale Militaire-Koninklijke Militaire School, 1000 Brussels, Belgium, TEC Partner)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
An important aim of W7-X is to demonstrate fast ion confinement at volume averaged beta values up to 5%, corresponding to plasma densities above 10^20 m^-3. Energetic H or D ions in W7-X with energies 50< E < 100 keV mimic alphas in a reactor. To this end, an ICRH system is prepared for W7-X ,with RF power up to ~1.5 MW at frequencies between 25-38 MHz in pulses up to 10 s. For optimal...
Mr
Dilip C Raval
(Institute for Plasma Research)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
SST-1 Tokamak was successfully commissioned in 2012 and the first plasma was achieved in June 2013 with poloidal limiters having SS 304L as vessel wall material. Due to plasma wall interactions, high-Z impurities released from the vessel wall which in turn cools the plasma by radiation loss. In order to reduce this effect, in 2nd phase of SST-1 refurbishment PFC components were installed in...
Dr
Alessio Morace
(Institute of Laser Engineering, Osaka University)
20/10/2016, 08:30
Fast Ignition (FI) is an alternative approach to Inertial Confinement Fusion (ICF) based on the separation between compression and heating of the equimolar Deuterium-Tritium (DT) fuel capsule. In the FI scheme, the heating is produced by an energetic particle beam, either ions or electrons, generated by an ultra-high intensity laser pulse.
Both in Proton and Fast Electron Fast Ignition high...
Mr
Dilip C Raval
(Institute for Plasma Research)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The SST-1 start- up studies and development of appropriate model has been initiated using electromagnetic field computation for active current carrying conductor and SST-1 vacuum vessel eddy characteristics. This electromagnetic model has been employed to predict individual electromagnetic field for active electromagnet such as vertical field coil (VF), poloidal field coil (PF), radial control...
Dr
Katsuhiro Ishii
(The Graduate School for the Creation of New Photonics Industries)
20/10/2016, 08:30
The progress of the target injection system is reported, where deuterated polystyrene (CD) beads are injected and engaged by implosion and heating laser beams at the repetition rate of 1 Hz. Since the high repetition rate experiments require to accurately position the injected pellets, for two years we have continuously tested and made the positions of the injected pellets better. Measuring...
Dr
Atsushi Kasugai
(National Institutes for Quantum and Radiological Science and Technology (QST/Rokkasho))
20/10/2016, 08:30
In the beam commissioning of the injector of linear IFMIF prototype accelerator (LIPAc) at the International Fusion Energy Research Center in Rokkasho, Japan the initial target performances was accomplished for Radio Frequency Quadrupole (RFQ) accelerator, of which assembling and commissioning will be started in 2016.
At present, 100 keV/120 mA/20% duty cycle deuterium and 50 keV/74 mA/10%...
Prof.
Takashi Kikuchi
(Nagaoka University of Technology)
20/10/2016, 08:30
Recent activities on heavy ion inertial fusion in Japan are reviewed in this paper. Particle accelerator development, beam dynamics research, interaction between heavy ions and target material, ion source development, and illumination scheme of heavy ion beams, for heavy ion inertial fusion, are reported.
Inertial confinement fusion scheme driven by intense heavy ion beams, so-called Heavy...
Prof.
NING DING
(Institute of Applied Physics and Computational Mathematics)
20/10/2016, 08:30
Fast Z-pinch has produced the most powerful X-ray radiation source in laboratory and also shows the possibility to drive inertial confinement fusion (ICF). The recent advances in the Z-pinch theoretical and numerical researches at the IAPCM are presented. We use a detailed circuit model to study the energy coupling between the generator and the Z-pinch process. With the full circuit model (FCL...
Dr
Eiichi Wakai
(Japan Atomic Energy Agency)
20/10/2016, 08:30
Small specimen test technology or technique (SSTT) towards design of fusion DEMO reactors was investigated and evaluated in the related studies of the International Fusion Materials Irradiation Facility / Engineering Validation and Engineering Design Activities (IFMIF/ EVEDA) project under Broader Approach (BA) Agreement between EURATOM and Japanese Government. The main results were described...
Dr
Andrey Litnovsky
(Forschungszentrum Juelich, Germany)
20/10/2016, 08:30
Due to its low sputtering yield, excellent thermal conductivity and low tritium uptake tungsten is currently deemed as most promising plasma facing material (PFM) for future power plant DEMO. However, in case of an accident the coolant supply may be damaged. The air can get into contact with PFMs during the air ingress. According to modeling, the temperature of PFMs can rise up to 1200oC due...
Mr
Jie Liu
(Institute of Applied Physics and Computational Mathematics)
20/10/2016, 08:30
We propose a feasible scheme to acquire high ion temperature and high thermal nuclear fusion neutron yield with laser ablated spherical convergent plasmas fusion (SCPF). In our scheme, we use intense lasers (1014-1015W/cm2) pulse of nanosecond duration to irradiate thermonuclear fuel (Carbonized Deuterium, CD)containing layer(~10microns) lined inside a spherical hohlraum, the fuel layer is...
Prof.
Qunying Huang
(CnINEST)
20/10/2016, 08:30
A program for fusion reactor structural material, i.e. the China Low Activation Martensitic (CLAM) program, aims to satisfy the material requirements for test blanket module (TBM) for ITER, China fusion engineering test reactor (CFETR) and fusion demonstration reactor (C-DEMO) in China. It has been undertaking by INEST (Institute of Nuclear Energy Safety Technology), CAS (Chinese Academy of...
Prof.
Akihiko Kimura
(Kyoto University)
20/10/2016, 08:30
Materials development is essential for realization of fusion DEMO reactor and beyond. High performance materials R&D has been conducted for the last several decades, and there have been made some remarkable technology innovations of fusion blanket structural material including first wall material. Among the several candidate blanket structural materials, oxide dispersion strengthened (ODS)...
Prof.
Irina Tazhibayeva
(KzIAE)
20/10/2016, 08:30
TThe research goal is irradiation of tungsten samples in hydrogen and post irradiation studies of the samples for microstructure change after irradiation and comparison with non-irradiated samples. The tungsten samples of DF-grade, double forged pure, were manufactured in Julich, Germany.
Irradiation of tungsten samples was carried out at the WWR-K reactor of Institute of Nuclear Physics,...
Dr
Riju Chavaramplackil Issac
(PG & Research Department of Physics, Mar Athanasius College, Mahatma Gndhi University, Kothamangalam, Kerala, India)
20/10/2016, 08:30
In this paper we present our experimental study for the development and investigation of suitable materials for protecting the IFE chamber wall from scattered laser light, energetic ions, electrons, neutrons, X-rays, etc. bombarding the chamber wall causing damage or activation in the wall material. We choose the carbon nanotubes for the following reasons. Carbon nanotubes with its structural...
788.
Temperature Sensitivity Analysis of Nuclear Cross Section using FENDL for Fusion-Fission System
Dr
Carlos Velasquez
(Universidade Federal de Minas Gerais)
20/10/2016, 08:30
Fusion energy has been presented as a clean alternative way of energy source. Furthermore, the neutronics features from fusion reactors make favorable the fuel regeneration and actinide transmutation due to the high-energy neutron flux. This work proposes a fusion-fission system (FFS) based on a Tokamak at operating temperature for transmutation of MA using reprocessed fuel by UREX+ technique...
Dr
Frederik Arbeiter
(Karlsruhe Institute of Technology)
20/10/2016, 08:30
Validation activities for key systems of the Lithium Facility and the Test Facility of the International Fusion Materials Irradiation Facility IFMIF were performed during the Engineering Validation and Engineering Design Activities phase 2007 - 2015 by Japanese and EU Research Units. A fully functional lithium loop with a 1:3 scaled target were constructed and run in Oarai, Japan. The lithium...
Dr
Andreas Dinklage
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Continuous fueling is a prerequisite for steady-state stellarator and heliotron fusion reactor operation. For 3D magnetic field configurations, outward directed thermodiffusion gives rise to density depletion in the hot plasma core which needs to be compensated by appropriate fuelling schemes. Pellet injection may generate particle sources relevant to the development of discharge scenarios...
Dr
Andrei Simakov
(Los Alamos National Laboratory)
20/10/2016, 08:30
Low-mode implosion asymmetry and hydrodynamic instabilities of the capsule are considered the main obstacles for achieving ignition in indirect drive inertial confinement fusion (ICF). Superior ablation properties of beryllium (Be) ablators as compared with plastic and diamond ablators may help overcome these obstacles. In particular, higher Be ablation pressure permits use of either thicker...
Dr
Mike Dunne
(IPP-Garching)
20/10/2016, 08:30
Scrape-off layer (SOL) properties are controlled by a number of parameters, such as heating power, main ion fuelling, and impurity seeding. The high field side high density (HFSHD) is a region of high density (~10× higher than the separatrix density) localised to the HFS SOL and is observed in both ASDEX Upgrade (AUG) and JET when a gas puff at sufficient heating power is applied. It can be...
Dr
Olaf Grulke
(MPI for Plasma Physics)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
The understanding of cross-field transport of particles and energy represents one of the most important challenges on the verge towards magnetic confinement fusion and is indispensable to extrapolate to next-generation devices. The Wendelstein 7-X (W7-X) stellarator, designed to operate quasi steady-state (pulse lengths up to 30min), has been optimized with respect to a reduction of...
Dr
Rita Lorenzini
(Consorzio RFX)
20/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
This work describes the development and the first applications of a new tool to study transport phenomena in fusion devices when magnetic islands are present.
Whether as large islands or narrow chains, magnetic islands change drastically the topology of the transport problem and the consequent strong modification of transport has effects that depend on the configuration under examination....
Dr
Jan Willem Coenen
(Forschungszentrum Juelich GmbH)
20/10/2016, 08:30
The development of advanced materials is essential for sophisticated energy systems like a future fusion reactor. For a fusion power plant multiple issues with respect to materials and components need to be evaluated. Brittle behavior is the limiting factors when operating any W based plasma facing components (PFCs) in a tokamak. This is particularly crucial when considering material...
Prof.
Yoneyoshi Kitagawa
(The Graduate School for the Creation of New Photonics Industries)
20/10/2016, 08:30
The recent key physics of the laser fusion is how to make hot sparks for the alpha burning in the dense core. The fast ignition is expected to form a hot spark even with a non-uniform illumination configuration, such as with a counter-illumination one. By using both a high-repetition rate 10 J laser and a single-shot kJ laser, we have proposed and demonstrated a new concept for the...
Dr
Hiroo Kondo
(Japan Atomic Energy Agency)
20/10/2016, 08:30
We report the validation results of liquid lithium target stability for an intense fusion neutron source, currently being planned as the International Fusion Materials Irradiation Facility (IFMIF), the advanced fusion neutron source (A-FNS), or the DEMO oriented neutron source (DONES). Thickness variation of the Li target must be suppressed to be within 1 mm inside a deuteron beam footprint to...
Zheng Yan
(University of Wisconsin- Madison)
20/10/2016, 09:10
Measurements of long wavelength (K_perp Rho_I<1) density fluctuation characteristics in the edge of both Deuterium (D) and Hydrogen (H) plasmas across the L-H transition on DIII-D demonstrate the existence of single or double bands of low-wavenumber turbulence observed near the edge of H and D plasmas, which are strongly correlated with the L to H-mode transition power threshold (P_LH) and can...
Dr
Manuel Garcia-Munoz
(Max-Planck Institute for Plasma Physics)
20/10/2016, 10:45
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Oral
A joint experimental effort on the DIII-D and ASDEX Upgrade (AUG) tokamaks shows that fast-ion confinement is quite sensitive to both edge localized modes (ELMs) and the externally imposed magnetic perturbations (MPs) used to mitigate ELMs.
In DIII-D, the role of plasma response to extermanlly applied MPs, and its impact on fast ion loss, is studied by varying the relative phase between...
Dr
Robert Akers
(UKAEA)
20/10/2016, 11:05
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Oral
ITER will be the first tokamak to enter the burning plasma regime and approach ignition; plasma heating will be dominated by 3.5MeV fusion-born alpha-particles and 1MeV Heating Neutral Beam (HNB) injected deuterons (together with a fast particle population resulting from ICRH). In this paper we describe a new Monte Carlo code, designed to simulate fast ion behavior on ITER in the presence of...
Dr
Cami Collins
(General Atomics)
20/10/2016, 11:25
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Oral
Recent experiments in the DIII-D tokamak show that many overlapping small-amplitude Alfvén eigenmodes (AEs) cause stiff fast-ion transport above a critical threshold. This result suggests that reduced models can be used to effectively predict alpha profiles, beam ion profiles, and losses to aid in the design of optimized scenarios for future burning plasma devices. Three key features of...
Dr
Alessandro Biancalani
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 11:45
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Oral
Alfvén Eigenmodes (AE) are global instabilities excited by energetic particles (EP) in magnetic fusion devices. AE can redistribute the EP population across flux surfaces, making the plasma heating less effective, and leading to additional loads on the walls. The interplay of AEs and EPs is investigated by means of gyrokinetic particle-in-cell simulations, with a nonperturbative approach. The...
Dr
Andreas Bierwage
(Japan Atomic Energy Agency (JAEA))
20/10/2016, 12:05
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Oral
Using the high-performance supercomputer Helios and advanced numerical methods, first-principle simulations of fast-ion-driven magnetohydrodynamic (MHD) modes have, for the first time, reproduced multiple cycles of so-called "Abrupt Large Events (ALE)" as observed in beam-driven high-beta JT-60 tokamak experiments. This is a major milestone because, unlike experiments, such simulations can...
Dr
Siriyaporn Sangaroon
(Department of Physics, Mahasarakham University, Mahasarakham, Thailand)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The tritium is considered as one of main fuels for D-T nuclear fusion reactors, where it is planned to be produced from a blanket of reactors by using the interactions between 14.1 MeV neutrons from nuclear fusion reactions and lithium from the blankets. In this work, the simulations of the tritium production from mock-up breeding blanket due to interactions of neutrons and lithium in the...
Dr
Clayton Myers
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
Halo currents are known to exhibit non-axisymmetric and rotating features in several devices including JET, Alcator C-Mod, DIII-D, ASDEX Upgrade, and NSTX. Such non-axisymmetries are of great interest to ITER because they can increase mechanical stresses during a disruption, especially if the rotation resonates with the natural frequencies of the vessel. This paper presents an ITPA-initiated...
Dr
Christian Hopf
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 14:00
Neutral beam current drive (NBCD) is an efficient option for non-inductive tokamak operation. With its eight 2.5 MW neutral beams of different geometry ASDEX Upgrade offers a versatile NBI system, well suited for current drive studies.
Past studies comparing on- and off-axis NBCD at 5 MW gave contradictory results. To understand the current profiles constrained by MSE anomalous fast-ion...
Dr
Felix Reimold
(Forschungszentrum Jülich)
20/10/2016, 14:00
Future fusion devices like ITER and DEMO will have to be operated with a detached divertor to meet material limits. Stable H-mode operation at high heating power $P_{Heat}/R = [5-12]MW m^{-1}$ with both targets completely detached, confinement of $H_{98}= 0.8 - 0.95$ and Greenwald fraction of $f_{GW}=0.7-0.9$ has been demonstrated with nitrogen seeding in the all-tungsten ASDEX Upgrade...
Dr
Adrianus Sips
(JET Exploitation Unit)
20/10/2016, 14:00
In the last two years the Integrated Operation Scenarios Topical Group (IOS-TG) of the ITPA IOS-TG has combined results of joint experiments with other data available at q95~3 in a database of global parameters with ~3300 entries of stationary discharges from AUG, C-Mod, DIII-D, JET and JT-60U for both carbon wall and metal wall experiments. The analyses focus on discharges that are stationary...
Dr
Brian LaBombard
(MIT)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The challenges that will be facing the divertor in a tokamak-based fusion reactor prompt the search for innovative divertor configurations that use non-standard magnetic geometry and additional X-points. Standard tokamak edge plasma transport codes such as UEDGE and SOLPS can be invaluable tools for exploration and evaluation of alternate divertor configurations for potential performance...
Dr
Ivo Furno
(EPFL- CRPP)
20/10/2016, 14:00
TORPEX is a flexible basic plasma device in which plasmas are created and sustained by microwaves at 2.45GHz using different gases. Different magnetic configurations of relevance for fusion are produced in TORPEX, including simple magnetized toroidal (SMT) configurations with a dominant toroidal field and a small vertical field component, or closed field-line configurations using a...
Dr
William Tang
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
Building the scientific foundations needed to develop fusion power in a timely way can be facilitated not only by familiar “hypothesis-driven”/ first principles approaches but also by engaging modern big-data-driven statistical methods featuring machine learning (ML). An especially time-urgent and very challenging problem facing the development of a fusion energy reactor today is the need to...
Prof.
Wonho Choe
(Korea Advanced Institute of Science and Technology)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Application of toroidally non-axisymmetric (3D) magnetic fields has great impacts on the heat transport onto divertor target. The 3D magnetic fields form stochastic field layers by opening magnetic islands, leading to modifications of magnetic field structure and heat flux distribution on the divertor. The heat flux splitting pattern strongly depends on the applied field configuration, which...
Dr
Vladislav V Plyusnin
(Instituto de Plasmas e Fusão Nuclear, IST, Universidade de Lisboa)
20/10/2016, 14:00
Report presents a survey of experiments on runaway electrons (RE) carried out recently in frames of EUROFusion Consortium in different tokamaks (Compass, ASDEX-Upgrade (AUG), TCV and JET). The increase of geometrical scale and physical parameters of plasma experiment on disruption generated RE has been studied. New data on disruption generated RE in Compass with carbon limiter and AUG with...
Dr
Naoko Ashikawa
(National Institute for Fusion Science)
20/10/2016, 14:00
Generation and accumulation of metal dust particles are important issues in material migration of the Plasma Facing Components (PFCs) such as tungsten (W) and Beryllium (Be) from viewpoints of the plasma operation, maintenance and safety in accidents for ITER and Demo. On the other hand, analysis results of the material components and the internal structure of the dust particle are few because...
Dr
Michael Komm
(Institute of Plasma Physics of the Czech Academy of Sciences)
20/10/2016, 14:00
The COMPASS tokamak is equipped with a set of high resolution diagnostics, which are capable of resolving the pedestal and hence contribute to the multi-machine scaling of the pedestal parameters. The first results obtained for a series of shots at q95 ~ 2.5 in 2015 confirmed that typical pedestal dimensionless parameters obtained at COMPASS are close to those achieved in a multi-machine...
Dr
Alexey Vertkov
(JSC “Red Star”)
20/10/2016, 14:00
Capillary-porous systems (CPS) with liquid Li, Ga, Sn and Sn-Li alloy is considered as alternative decision under development of plasma facing elements (PFE) for DEMO-type fusion reactor and fusion neutron source. The main advantages of liquid low melting metals in matrix of CPS with respect to solid materials are the possibility to provide surface self-restoring and high resistance to...
Dr
Cami Collins
(General Atomics)
20/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Recent experiments in the DIII-D tokamak show that many overlapping small-amplitude Alfvén eigenmodes (AEs) cause stiff fast-ion transport above a critical threshold. This result suggests that reduced models can be used to effectively predict alpha profiles, beam ion profiles, and losses to aid in the design of optimized scenarios for future burning plasma devices. Three key features of...
Dr
Justyna Grzonka
(Warsaw University of Technology)
20/10/2016, 14:00
Comprehensive and systematic surveys of dust particles were performed at JET with the ITER-Like Wall (JET-ILW) after two experimental campaigns, ~19 h of plasma each. Thought the total amounts removed were small (around 1g) the study of dust categories is crucial for ITER because these are unique data from a full metal-wall (beryllium and tungsten) machine. The identification of various...
Mr
Tianyang XIa
(Institute of Plasma Physics, Chinese Academy of Sciences)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
In this paper we report the simulations of the evolution of heat flux deposition and turbulence in edge plasma region for the ELMy H-mode discharges of EAST, C-Mod and DIII-D. The divertor sheath boundary conditions have been implemented into the BOUT++ six-field two-fluid model based on the Braginskii equations with non-ideal physics effects. This module has shown the comparable transient...
Dr
Aleksey Arakcheev
(Budker Institute of Nuclear Physics)
20/10/2016, 14:00
Simulations of transient heat load corresponding to unmitigated ELMs type I in ITER divertor are performed on novel material test facility developed at the Budker Institute of Nuclear Physics. Employing of intense long pulse (0.1-0.3 ms) electron beam as a heating source results in relative low light emission by the ablation plume hence facilitates imaging of the tungsten target during the...
Dr
Paola Mantica
(Istituto Di Fisica Del Plasma, Consiglio Nazionale delle Ricerche (CNR), 20125 Milan, Italy)
20/10/2016, 14:00
The TEM driven electron heat transport has been investigated experimentally in JET C-wall L-mode plasmas with dominant ICRH electron heating, by flux scans at constant total electron power and power modulation using ICRH in (3He)-D mode conversion scheme. The dependence of the TEM threshold on s and q has been studied by implementing ad hoc time waveforms of the plasma current in order to...
Mrs
Juan Huang
(CnIPPCAS)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
On the EAST tokamak, resonant magnetic perturbations (RMPs) have been successfully applied to control edge localized mode (ELM) [1]. To quantify the impact of the resulting 3D magnetic field structure on the edge plasma transport, the EMC3-EIRENE code [2] is employed, which is a coupled code package of EMC3 for fluid ions and electrons and EIRENE for kinetic neutrals. The code had been applied...
Dr
Dmitiriy Borodin
(Forschungszentrum Jülich GmbH)
20/10/2016, 14:00
Erosion will be one of the main factors determining the lifetime of the plasma-facing components (PFCs) in ITER, particularly the low Z beryllium (Be) first wall (FW). This paper presents the tests of Be erosion data during experiments with the ITER-Like Wall (ILW) in JET and the corresponding re-visiting of the predictive modelling for ITER. The key tool is the Monte-Carlo 3D impurity...
Dr
Alberto Loarte
(ITER Organization)
20/10/2016, 14:00
In order to evaluate if W accumulation is expected in ITER plasma conditions and whether the available heating systems can provide the degree of control required for stable H-mode operation we have applied integrated plasma models (ASTRA and JINTRAC) to a wide range of plasma conditions in ITER including confinement transients (i.e. L-H and H-L transitions). The studies find that, in agreement...
Dr
Florian Koechl
(Vienna University of Technology, Institute of Atomic and Subatomic Physics)
20/10/2016, 14:00
Operation of tokamaks with W PFCs presents specific challenges for impurity control. Lack of impurity control can lead to a radiative collapse due to W accumulation and increased disruptivity. W accumulation in stationary H-mode can be avoided by controlled ELM triggering and central RF heating. Such schemes are also expected to be effective in ITER. However, the control of W transport can be...
Prof.
Jaime Mora-Meléndez
(Instituto Tecnológico de Costa Rica)
20/10/2016, 14:00
Since 2009, the Instituto Tecnológico de Costa Rica started a research project on stellarators which aims at designing, constructing and implementing the first device of this technology in Latin America. SCR-1 is a small-size, modular stellarator (Major radius=0.238 m, plasma radius=0.059 m, aspect ratio>4.4, expected plasma volume ≈ 0.016 m^3, 10 mm thickness 6061-T6 aluminum vacuum vessel)....
Dr
Andreas Bierwage
(National Institutes for Quantum and Radiological Science and Technology)
20/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Using the high-performance supercomputer Helios and advanced numerical methods, first-principle simulations of fast-ion-driven magnetohydrodynamic (MHD) modes have, for the first time, reproduced multiple cycles of so-called "Abrupt Large Events (ALE)" as observed in beam-driven high-beta JT-60 tokamak experiments. This is a major milestone because, unlike experiments, such simulations can...
Prof.
Marek Rubel
(Royal Institute of Technology (KTH), Stockholm, Sweden)
20/10/2016, 14:00
M. Rubel
EUROfusion Consortium, JET, Culham Science Centre (CSC), Abingdon, OX14 3DB, UK
Royal Institute of Technology (KTH), 100 44 Stockholm, Sweden
All plasma-facing components in ITER will be castellated. A large scale test of castellated PFC is carried out at the JET tokamak which has been operated since year 2011 with the metal ITER-Like Wall (JET-ILW). This contribution is...
Gabriella Pautasso
(IPP, Garching, Germany)
20/10/2016, 14:00
Plasma disruptions, occurring above a given plasma current and thermal energy, will have to be mitigated in ITER, to avoid or suppress runaway electrons, reduce thermal and mechanical stresses on the machine components, and mitigate their damage. The necessary conditions for the fulfillment of – what is called here - the Disruption Mitigation Function (DMF) are, firstly, the capability of...
Prof.
João P. S. Bizarro
(Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Anomalous transport, turbulence and generation of large-scale structures in the scrape-off layer (SOL) of tokamaks are some of the main issues that control machine performance (via impurity contamination) and the life expectancy of plasma-facing materials, and here one tries to achieve some understanding of these questions through the theoretical analysis of a reduced two-dimensional two fluid...
Dr
Alessandro Biancalani
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Alfvén Eigenmodes (AE) are global instabilities excited by energetic particles (EP) in magnetic fusion devices. AE can redistribute the EP population across flux surfaces, making the plasma heating less effective, and leading to additional loads on the walls. The interplay of AEs and EPs is investigated by means of gyrokinetic particle-in-cell simulations, with a nonperturbative approach. The...
Dr
Robert Akers
(UKAEA)
20/10/2016, 14:00
THW - Magnetic Confinement Theory and Modelling: Wave–plasma interactions; current drive; heating; energetic particles
Poster
ITER will be the first tokamak to enter the burning plasma regime and approach ignition; plasma heating will be dominated by 3.5MeV fusion-born alpha-particles and 1MeV Heating Neutral Beam (HNB) injected deuterons (together with a fast particle population resulting from ICRH). In this paper we describe a new Monte Carlo code, designed to simulate fast ion behavior on ITER in the presence of...
Dr
Sven Wiesen
(Forschungszentrum Jülich)
20/10/2016, 14:00
JET ITER-like wall (ILW) experiments show that the edge density evolution is linked with the level of recycling as with increasing density a delay is observed before pedestal recovery after an ELM. Poor confinement in high-density baseline scenarios can be partially mitigated by choosing divertor plasma configurations with the strike-lines close to the divertor corners with enhanced pumping....
Dr
Hiroki Hasegawa
(National Institute for Fusion Science)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
It is firstly demonstrated that transport of impurity particles are caused by blob and hole propagations by means of the three dimensional (3D) electrostatic Particle-in-Cell (PIC) simulations. We have shown that (1) the impurity profile in the blob / hole structure becomes biased shape like a dipole and (2) the biased density profile of impurity propagates with the blob / hole. The "blob" and...
Dr
Alexei POLEVOI
(ITER Organization)
20/10/2016, 14:00
ELM mitigation for divertor protection is one of the main factors affecting plasma fuelling and detachment control at full current operation. Here we derive the scaling for the operational space, where the ELM mitigation for divertor protection is not required and parameters of ELM-pacing pellet injection are determined by the tungsten control. The scaling eliminates the uncertainty connected...
Dr
Joydeep Ghosh
(Institute for Plasma Research)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Neutral particle behavior in Aditya tokamak, which has a circular poloidal ring limiter at one particular toroidal location, has been investigated using DEGAS2 code [1]. The code calculations are based on Monte Carlo algorithms and mainly used in the various tokamaks with divertor configuration. This code has been successfully implemented in Aditya tokamak with limiter configuration and the...
Prof.
Jean-Marie Noterdaeme
(Max-Planck-Institute for Plasma Physics)
20/10/2016, 14:00
The coupling of power in the Ion Cyclotron Range of Frequency to the plasma has encountered challenges, which can be classified into two broad ranges of categories: the sensitivity to the plasma edge density profile with the difficulty to couple power to the plasma and the enhanced plasma-antenna interaction with, among others, the resulting impurity production.
We report on the recent...
Dr
Marc Goniche
(CEA, IRFM)
20/10/2016, 14:00
Development of high performance plasma scenarios in high Z metal plasma-facing environment is hampered by an unfavourable distribution of these particles across the plasma core, known as ‘core accumulation’. Tungsten core profiles have been analysed in different JET scenarios (Ip=2.5-4.0MA, Ptot=18-30MW) with ICRH (0-6MW, H minority heating) from the soft X-ray diagnostic.
At a plasma...
Dr
Eleonora Viezzer
(Max-Planck-Institut fuer Plasmaphysik)
20/10/2016, 14:00
The gradients in the ion and electron temperature profiles, Ti and Te, are a key component for
driving turbulent transport in plasmas. Since the 1980s, ‘profile resilience’ has been observed on
many tokamaks, which describes the fact that Ti and Te are limited by a critical normalized temperature gradient. Beyond this critical R/LT the heat diffusivities increase drastically. Hence, with...
Dr
Kristel Crombe
(Ghent University, Belgium)
20/10/2016, 14:00
IShTAR (Ion Sheath Test ARrangement) is dedicated to the investigation of the interactions between
an ICRF antenna and a plasma in the conditions (plasma temperature and density, magnetic
configuration) representative of the plasma edge of a magnetic confinement fusion machine. The
test bed is composed of a helicon plasma source and a main vessel, in which a dedicated single strap
ICRF...
Mr
Shohei Yamoto
(Faculty of Science and Technology, Keio University, Japan)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
With the move in current and future fusion devices to all-metal walls, and particularly with tungsten (W) plasma-facing components, understanding heavy ion impurity transport processes in the Scrape-Off Layer (SOL)/divertor region is becoming one of the most critical issues for tokamak operation. To improve this understanding, we are continuing to develop the kinetic SOL/divertor impurity...
Mr
Randy Churchill
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Simulations using the fully kinetic code XGCa were undertaken to explore the impact of kinetic effects on scrape-off layer (SOL) physics in DIII-D H-mode plasmas. XGCa is a
total-f, gyrokinetic code which self-consistently calculates the axisymmetric electrostatic potential and plasma dynamics, and includes modules for Monte Carlo neutral transport. Fluid simulations are normally used to...
738.
Long-term fuel retention and release in JET ITER-Like Wall at ITER-relevant baking temperatures
Dr
Kalle Heinola
(University of Helsinki)
20/10/2016, 14:00
JET with its ITER-Like Wall (ILW) material configuration is presently the only machine in which ITER-relevant plasma-material interactions, such as material erosion and migration and in-vessel fuel retention and removal, can be studied on the tokamak-scale. Especially the in-vessel tritium (T) retention in ITER has high safety importance. The ITER baseline to recover the trapped T is to...
Dr
Valentin Igochine
(Max-Planck-Institute for Plasma Physics, Garching, Germany)
20/10/2016, 14:00
The improved H-mode scenario (or high β hybrid operations) is one of the main candidates for high-fusion performance tokamak operation, which could potentially reach the steady-state condition. In this case, the normalized pressure β_N must be maximized and pressure driven instabilities limit the plasma performance. These instabilities could have either resistive ((m=2,n=1) and (3,2)...
Mr
riccardo roccella
(ITER Organization)
20/10/2016, 14:00
The causes of plasma asymmetries and rotation during disruptions are still an open issue even though their effects are clearly seen on present machines like JET where the vessel has been observed to move horizontally during asymmetric VDEs. Strong horizontal forces are then expected to be related to the plasma asymmetries. In ITER, loads caused by asymmetric VDEs are expected to be among the...
Dr
Andreas Kirschner
(DeIECR)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Tungsten is a promising first wall material in fusion devices. Though, due to its high atomic number, tungsten concentration levels in the plasma core have to be kept small. However, in addition to low sputtering yields the high atomic number has the beneficial effect of prompt deposition, i.e. depending on the plasma parameters large amounts of sputtered tungsten can be deposited during the...
Dr
Peter De Vries
(ITER Organization)
20/10/2016, 14:00
The controlled shutdown is an often overlooked, though important, phase of the tokamak discharge. The dynamics during this phase complicate control, making it difficult to avoid operational limits, which in the worst case, may lead to a disruption. This is exacerbated by the fact that at the end of the discharge the device is already operated close to many of its technical limits. For...
Dr
Rodolphe D'Inca
(MaxPlanck Institute for Plasma Physics)
20/10/2016, 14:00
Ion Cyclotron Emission (ICE) is an instability triggered by the resonant interaction between a population of fast ions and waves supported by the background plasma. The analysis of the signal passively measured with Radio-Frequency probes in time and frequency domains can provide information on the characteristics of the barely trapped and lost fusion alpha-particles in a machine such as ITER....
Dr
Nicolas Mellet
(PIIM, CNRS/Aix-Marseille Univ., France)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Power exhaust constitutes one of the primary challenges for future fusion devices. Given the fact that scaling parameters have not been clearly identified, the prediction for divertor plasma conditions relies mainly on simulation with transport edge codes like Soledge2D-Eirene that is used in the present work. For charged species, treated with a fluid model, the simulation domain does not...
Daren Stotler
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Neutral particle recycling effect on the edge ITG (ion temperature gradient) turbulence has been studied in a realistic tokamak geometry with a steep edge pedestal, using a full-f edge gyrokinetic code XGC1. The ITG turbulence is chosen here because it is the most
fundamental and robust form of tokamak plasma instability, with its long radial correlation length influencing other turbulence in...
Mr
Henri Weisen
(JET EFDA)
20/10/2016, 14:00
The ability to calculate and predict the neutron yield is essential for the planning of fusion experiments, such as the future Deuterium/Tritium experiment in JET. The fusion yield expected in JET from fast ion orbit calculations using NUBEAM/TRANSP has been systematically compared to the measurements from a set of three Uranium fission chambers, which were recalibrated in 2013. In many JET...
Xueqiao Xu
(Lawrence Livermore National Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Simulations with the BOUT++ code have been used to study the energy loss for edge localized modes (ELMs) at different collisionality & electric field Er shear and to investigate the controls of transition to different ELM and quiescent H-mode (QH-mode) regimes. The simulation results indicate that by development of a flexible Er control capabilities, it is conceivable that tokamak operation...
Dr
Roman Zagorski
(Institute of Plasma Physics and Laser Microfusion)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
JT-60SA is a superconducting tokamak supporting fusion research on the way towards realization of energy production in a DEMO reactor. The baseline JT-60SA design foresees full carbon wall, however feasibility studies have been initiated recently to assess the possibility of the transition to full W. In this paper, JT-60SA reference design scenarios at high (#3) and low (#2) density have been...
Mr
Florian Effenberg
(Department of Engineering Physics, University of Wisconsin - Madison)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Heat flux mitigation and power dissipation is a crucial and challenging topic in the 3-D environment of stellarator devices foreseen for steady state operation. We show that the limiter startup configuration of the first quasi-isodynamic optimized stellarator Wendelstein 7-X features a complex helical scrape-off layer topology of helical scrape-off layer flux bundles of three different...
Dr
Joseph Snipes
(ITER Organization)
20/10/2016, 14:00
The Preliminary Design of the ITER Plasma Control System (PCS) has been carried out since 2014 by members of the ITER Organization and a number of plasma control experts from CCFE, CEA-Cadarache, CREATE, Efremov, General Atomics, IPP-Garching, and Kurchatov as well as through a collaboration with Eindhoven University of Technology. This work builds on the PCS Conceptual Design that was...
Dr
Kenzo Ibano
(Osaka University)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Erosions of the wall materials via melting, sputtering, and vaporization caused by the intense pulsed heat loads during ELMs and disruptions in the fusion devices are the serious concern. At the same time, experimental observations have shown that the intense heat flux causes the formation of vapor layer which dissipates further incoming plasma heat-flux. Understandings on these...
Prof.
Isao Katanuma
(University of Tsukuba)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
It is understood that plasma blobs produced near a separatrix are responsible for the most radial transport of plasma density in SOL. Particle simulation was first performed on a blob from its production to the propagation. The particle simulation uses the (2 and 1/2) dimensional electrostatic implicit code with 256 x 128 meshes. Ions (electrons) are distributed to have a tanh(x) density...
Mr
Frederic Clairet
(CEA)
20/10/2016, 14:00
Plasma turbulence is a key parameter governing the confinement quality of magnetically confined plasmas. It is responsible of a substantial particle and heat transport that affects the performance of a nuclear fusion device. More detailed knowledge and understanding are constantly needed and requires more and more precise measurements with, in turn, improved diagnostic performance. Swept...
Dr
Jeremy Lore
(ORNL)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The 3D edge transport code EMC3-EIRENE is used to test magnetic field models with and without plasma response against experimental data on DIII-D and NSTX for a range of collisionalities, including the transition to detachment. None of the models tested can quantitatively reproduce the measured ‘lobe’ structure in the scrape off layer (SOL) temperature and density while maintaining the...
Markus Weiland
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 14:00
Fast, supra-thermal ions provide a powerful mechanism to heat fusion plasmas and to drive plasma currents and rotation. It is therefore crucial for the success of future fusion devices (such as ITER and DEMO) to understand the physics of fast ions and ensure their safe confinement. In the presented work, experimental studies of the fast-ion phase space are carried out using a FIDA (Fast-Ion...
Prof.
Piero MARTIN
(Consorzio RFX)
20/10/2016, 14:00
EUROfusion dedicates a significant effort to disruption and runaway electron (RE) research in its Medium Size Tokamaks (MST) Task Force, which coordinates the European activities in ASDEX-Upgrade (AUG), MAST-U and TCV. The MST disruption and RE programme addresses prediction, avoidance and mitigation.
Experiments on disruption mitigation utilize Massive Gas Injection (MGI) systems in AUG and...
Dr
David Humphreys
(General Atomics)
20/10/2016, 14:00
Control analysis and design tools developed at DIII-D [1] have been applied to ITER in studies supporting design of the ITER Plasma Control System (PCS) [2] to prepare for the upcoming PCS Preliminary Design Review (PDR). These studies include assessment of an extremum-seeking approach to real-time error field correction, advances in vertical controllability metrics, simulation of plasma...
Dr
Michael Lehnen
(ITER Organization)
20/10/2016, 14:00
Successful operation of ITER and a timely achievement of its objectives require an accurate disruption management as the significant disruption loads can have severe impact on the availability of the device and the lifetime of the in-vessel components. Target values for the disruption rate and the mitigation success rate will have to be defined for each of the different operational phases....
Prof.
Ahmed Hassanein
(Purdue University)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Plasma-material interaction (PMI) in future Tokamak fusion devices such as ITER is probably the most critical issue in the development of fusion power and a serious obstacle that is difficult to overcome. Plasma instability events such as disruptions, resulting runaway electrons, edge-localized modes (ELM), and vertical displacement events (VDE) are all very serious events and potentially the...
Dr
Xianzhu Tang
(Los Alamos National Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The divertor and first wall surface not only recycles the plasma particles
as returned neutrals
but also returns a portion of the impacting ion kinetic energy to the
plasma. Unlike carbon tiles, tungsten walls, for the much larger atomic mass,
mostly reflect the impacting light ions and hence recycle a majority
of the plasma ion kinetic energy.
This hinders the plasma energy exhaust and...
Dr
Matthias Willensdorfer
(Max Planck Institute for Plasma Physics)
20/10/2016, 14:00
At ASDEX Upgrade ELM mitigation using external magnetic perturbations has been achieved at high plasma densities (n_e/n_GW > 0.65, corresponding to nu*>1.2) and, more recently, at low pedestal collisionality (nu*<0.4) accompanied with density pump-out. To investigate the interaction between the plasma response and ELM mitigation, comprehensive experiments using various plasma configurations...
Dr
Mikhail Tsventoukh
(Lebedev Physical Institute RAS)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Intense plasma-surface interactions are accompanied not only by simple surface erosion and by the plasma pollution, but it also can lead to the intense collective phenomena of the electrical discharge that maintains at the first wall and derives the energy from the main plasma.
As the fusion plasma typically contains a lot of energy and exhibits intense plasma splashes, e.g. in the ELM form,...
Dr
Antti Hakola
(VTT Technical Research Centre of Finland Ltd.)
20/10/2016, 14:00
The possible start-up phase of ITER with helium plasmas has set the need to understand in detail the interaction between tungsten plasma-facing components (PFCs) and helium. In addition, a smooth start of He plasma operations requires cleaning the vessel wall from residual fuel species and other impurities. To this end, Ion Cyclotron Wall Conditioning (ICWC) is a promising method. We have...
Prof.
Paolo Ricci
(SPC-EPFL)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The GBS code has been developed in the last few years to simulate plasma turbulence and neutral atom dynamics in SOL conditions. GBS advances the drift-reduced Braginskii equations for low-frequency plasma turbulence, solving at the same time a kinetic equation of neutral atoms by the method of characteristics. In GBS the plasma dynamics is evolved as the interplay between plasma sources (due...
Dr
Patrick Tamain
(CEA Cadarache)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Mean-field transport codes are the key tools for the understanding of Scrape-Off-Layer and divertor regimes. They rely on models in which simple closures are used to model average fluxes and stresses due to fluctuations. In particular, turbulent transport is commonly described via a gradient-diffusion hypothesis and ad-hoc diffusion coefficients. However, these coefficients differ from one...
Dr
Andreas Kirschner
(DeIECR)
20/10/2016, 14:00
Plasma-wall interaction in fusion devices results in material erosion of the first wall, its migration and deposition. According to the present knowledge, tritium contained in the co-deposited layers is responsible for the major part of the in-vessel tritium inventory.
A set of quartz crystal microbalance (QMB) was used at JET with full carbon wall to monitor material erosion/deposition rates...
Dr
Jonathan Citrin
(FOM DIFFER - Dutch Institute for Fundamental Energy Research)
20/10/2016, 14:00
A realtime capable core turbulence tokamak transport model is developed, extending a previous proof-of-principle (J.Citrin, S.Breton et al., Nucl. Fusion 55 092001, 2015). This model emulates a quasilinear gyrokinetic turbulent transport code, via regularized nonlinear regression using neural networks. Calculation of transport fluxes for the entire radial profile is achieved at sub-millisecond...
Dr
Dirk Van Eester
(LPP-ERM/KMS)
20/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Ion cyclotron resonance heating (ICRH) is a powerful and flexible method, which can make a significant contribution to a future DT campaign on JET. It can be used for direct fuel ion heating or for minority ion heating, in the latter case leading to electron heating via Coulomb collisions of the fast minority ions with the electrons. Some ICRH schemes can also directly enhance nuclear reaction...
Dr
Elena de la Luna
(CIEMAT)
20/10/2016, 14:00
Recent experiments on JET with the ITER-like wall (ILW) show that divertor pumping is a key element to access good confinement at high triangularity in scenarios where high gas injection rates are required to keep W core radiation within acceptable limits (for plasma current above 1.5 MA). Similar to previously reported observations at low-triangularity, the use of a configuration where the...
Dr
Régis Bisson
(Aix-Marseille Université, CNRS, PIIM UMR 7345)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Fusion fuel trapping (retention) and release from plasma facing components (PFC) is one of the critical issues for ITER and for any future industrial demonstration reactor such as DEMO. Therefore, understanding fundamental mechanisms behind hydrogen isotopes retention in first wall materials is necessary. We developed an approach that couples dedicated experimental studies with modelling at...
Dr
Jon Hillesheim
(Culham Centre for Fusion Energy)
20/10/2016, 14:00
Unraveling the conditions that permit access to H-mode continues to be an unresolved physics issue for tokamaks. The scaling of the L-H transition power threshold, P_LH, to future devices has considerable uncertainty. Experiments have been performed in JET, with the ITER-like W/Be wall, to investigate the dependencies of P_LH and also to probe the underlying physics of the transition including...
Mr
Ammar Hakim
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
We present a new gyrokinetic code, Gkeyll, for use in edge plasma
simulations. The code implements energy conserving discontinuous
Galerkin schemes, applicable to a general class of Hamiltonian
equations. Several applications of our code to various test problems
are presented. We compute the parallel heat-flux on divertor plates
resulting from an ELM crash in JET, for a 1D/1V SOL...
Dr
Michael Campanell
(Lawrence Livermore National Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Electron emission from surfaces is important in many plasma applications. Recently, it was shown that a fundamentally distinct plasma-surface interaction regime denoted the “inverse regime” [1] occurs when the emission coefficient exceeds unity. An inverse regime might arise in divertors because secondary and thermionic emission from divertor plates are intense under certain operating...
717.
Study of the Effect of Magnetic Expansion in Snowflake Divertor on Impurity Screening for CFETR
Prof.
Minyou Ye
(School of Nuclear Science and Technology,cnUSTC)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Snowflake divertor is considered as a possible choice for CFETR design due to its dramatic ability in reducing the peak heat load onto divertor targets. It was pointed out that, such a reduction of peak heat load is due to both larger plasma-wetted area and larger fraction of power radiated in the edge [M.V. Umansky, et al., Nucl. Fusion 49 (2009) 075005]. Therefore, to achieve the best level...
Mr
Xavier Garbet
(CEA)
20/10/2016, 14:00
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
This paper investigates the interplay of neoclassical, turbulent and MHD processes, which are simultaneously at play when contributing to impurity transport. It is shown that these contributions are not additive, as assumed sometimes. The interaction between turbulence and neoclassical effects leads to less effective thermal screening, i.e. lowers the outward flux due to temperature gradient....
Dr
Andreas Stegmeir
(Max-Planck-Institute for Plasma Physics)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The complex geometry in the edge and scrape-off layer poses a challenge to simulations of magnetically confined plasmas, since the usually employed field/flux-aligned coordinates become singular on the separatrix/X-point.
A field line map approach (see also flux-coordinate independent approach) offers a promising solution to these problems. The approach is based on a cylindrical grid, which...
Dr
Marco Valisa
(Consorzo RFX)
20/10/2016, 14:00
Experimental and modeling activities have started at JET in order to carry out an assessment of the physics mechanisms that control the penetration of high Z impurities from the divertor into the core plasma and to provide firm physics basis for the ELM-control requirements in ITER. The experiments are based on the injection of traces of extrinsic impurities in various ELMy plasmas, thus...
Dr
Manuel Garcia-Munoz
(Max-Planck Institute for Plasma Physics)
20/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
A joint experimental effort on the DIII-D and ASDEX Upgrade (AUG) tokamaks shows that fast-ion confinement is quite sensitive to both edge localized modes (ELMs) and the externally imposed magnetic perturbations (MPs) used to mitigate ELMs.
In DIII-D, the role of plasma response to extermanlly applied MPs, and its impact on fast ion loss, is studied by varying the relative phase between the...
Dr
Yannick Marandet
(PIIM, CNRS/Aix-Marseille Univ., Marseille, France, EU)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Power exhaust is one of the major challenges that future devices such as ITER and DEMO will face. Because of the lack of identified scaling parameters, predictions for divertor plasma conditions in these devices have to rely on detailed modeling. Most plasma edge simulations carried out so far rely on transport codes, which consist of a fluid code for the plasma coupled to a kinetic Monte...
Dr
Thomas Pütterich
(Max-Planck-Institut für Plasmaphysik)
20/10/2016, 14:00
The radial electric field E_r at the plasma edge and its relation to plasma turbulence is investigated throughout the LH-transition and an ELM cycle. Various diagnostics are considered including an upgraded charge exchange recombination spectroscopy system. The latter is able to measure impurity temperature, flow and density profiles with a frequency of up to 20kHz and a radial resolution of...
Zheng Yan
(University of Wisconsin- Madison)
20/10/2016, 14:00
Measurements of long wavelength (K_perp Rho_I<1) density fluctuation characteristics in the edge of both Deuterium (D) and Hydrogen (H) plasmas across the L-H transition on DIII-D demonstrate the existence of single or double bands of low-wavenumber turbulence observed near the edge of H and D plasmas, which are strongly correlated with the L to H-mode transition power threshold (P_LH) and can...
Dr
Peter Manz
(Max-Planck Institut für Plasmaphysik)
20/10/2016, 14:00
The I-mode is an improved confinement regime of tokamak plasmas operating in the unfavorable
ion gradB-drift direction combining H-mode-like energy confinement with L-mode-like particle and impurity transport [1]. To qualify the I-mode as an operating scenario for ITER threshold and accessibility studies [2] also on a multi-machine basis [3] are needed. Even if the I-mode might not be...
Dr
Seung-Hoe Ku
(Princeton Plasma Physics Laboratory)
20/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
The importance of the nonlinear "blobby" turbulence (or "intermittent plasma objects") in the scrape-off layer (SOL) of the tokamak plasma has been well known. Blobs are usually measured and discussed for L-mode edge/SOL plasmas and inter-ELM SOL plasmas. However, blobs are also known to exist in steep H-mode pedestals. From ITER’s perspective, understanding the H-mode blobs may be more...
Dr
Shinsuke Fujioka
(Institute of Laser Engineering, Osaka University)
20/10/2016, 14:20
Here we report recent experimental results relevant to the fast ignition (FI) inertial confinement fusion assisted with external kilo-tesla magnetic field. We have experimentally observed generation of 0.6 kT of magnetic field by using laser-driven capacitor-coil scheme, short diffusion time (<< 1 ns) of laser-generated magnetic field into a target material, reduction of the REB beam diameter...
Dr
Johan Frenje
(Massachusetts Institute of Technology)
20/10/2016, 14:40
Hot-spot ignition planned at the National Ignition Facility (NIF) requires proper assembly of the DT fuel, as manifested by the evolution of areal density (ρR) symmetry and hot-spot ion temperature (Ti). Ideally, a spherically symmetric layer of cold and dense fuel with a ρR exceeding 1 g/cm2 surrounding a ~5 keV lower-density hot spot is obtained at peak convergence. To reach these...
Prof.
Akifumi Yogo
(Institute of Laser Engineering, Osasa University)
20/10/2016, 15:00
Fusion fast ignition assisted by laser-driven ion beams requires 10 kJ energy deposition onto the fuel core having ~500 g/cm^3 densities. Assuming 100 kJ as a technically manageable energy of the driving laser, the first milestone can be found on 10% conversion efficiency from the laser energy into ions having kinetic energies of 10-30 MeV/u.
In this paper, we experimentally investigate the...
Hans Rinderknecht
(Lawrence Livermore National Laboratory)
20/10/2016, 15:20
Implosions of thin-shell capsules produce strongly-shocked (M > 10), low-density (ρ ~ 1 mg/cc), high-temperature (Ti ~ keV) plasmas, comparable to those produced in the strongly-shocked DT-vapor in inertial confinement fusion (ICF) experiments. A series of thin-glass targets was filled with mixtures of deuterium and Helium-3 gas ranging from 20% to 100% deuterium and imploded on the OMEGA...
Prof.
Junji Kawanaka
(Institute of Laser Engineering, Osaka University)
20/10/2016, 15:40
A new heating laser for fast ignition, called the LFEX-Laser, has been demonstrated with all four beams. The obtained total pulse energy was 2 kJ for a 1 ps pulse duration. The peak power of 2 PW is the highest of all kilojoule lasers in the world and was achieved with a high intensity contrast ratio of 1 × 10^10.
To increase the pulse energy to the kilojoule class in a short pulse of 1–2 ps,...
Dr
roger stoller
(oak ridge national laboratory)
20/10/2016, 16:40
In addition to the engineering challenges associated with building and operating any complex facility, a range of critical materials issues must be addressed in order to make fusion power commercially viable. These include: (1) developing structural materials with suitably long lifetimes, (2) obtaining a plasma-facing material with sufficient ductility and low tritium retention, and (3)...
Mr
GUANG-NAN LUO
(Institute Of Plasma Physics, Chinese Academy Of Sciences)
20/10/2016, 17:00
A. The first EAST plasma was ignited in 2006 with non-actively-cooled steel plates as plasma-facing materials and components (PFMC) which was then upgraded into full graphite tiles bolted onto water-cooled copper heat sinks in 2008. And the first wall was changed further into TZM in 2012, while keeping graphite for both of the upper and lower divertors. With rapid increase in H&CD power in...
Dr
Anna Widdowson
(UKAEA)
20/10/2016, 17:20
Post mortem analysis of components removed from the JET ITER-like wall (JET-ILW) provides an overall picture of long term fuel inventory. Results from the first 2011-12 (ILW-1) and second 2013-14 (ILW-2) JET-ILW campaigns are now available making a comprehensive overview possible. Overall plasma times for ILW-1 and ILW-2 are similar: ~ 6 hours limiter plasma and ~14 / ~13 hours divertor...
Yuri Shpanskiy
(NRC "Kurchatov Institute")
20/10/2016, 17:40
Fusion-fission hybrid facility based on superconducting tokamak DEMO-FNS is developed in Russia for integrated commissioning of steady-state and nuclear fusion technologies at the power level up to 40 MW for fusion and 400 MW for fission reactions. The project status corresponds to transition from conceptual design to engineering one. This facility is considered in RF as the main source of...
Prof.
Zengyu Xu
(Southwestern Institute of Physics)
20/10/2016, 18:20
After obtaining a full-coverage free curve-surface flow by curve plate with three layer meshes, new experimental results showed that a full-coverage free surface flow can’t be obtained by a flat plate with meshes. More were recently investigated on MHD effects of other free surface flows flowing on flat plate. Base on the experimental data and newly developed modeling method, other way is...
Dr
Mark Gilbert
(CCFE)
21/10/2016, 08:30
FNS - Fusion Nuclear Physics and Technology
Poster
Inventory calculations have a key role in designing future fusion power plants because, for a given irradiation field and material, they can predict the time evolution in chemical composition, activation, decay heat, gamma-dose, gas production, and even damage (dpa) dose. For conceptual designs of the European DEMO fusion reactor such calculations can provide information about the neutron...
Dr
Keii Gi
(Research Institute of Innovative Technology for the Earth (RITE))
21/10/2016, 08:30
Climate change has become one of the most important issues to be tackled in the world. Deep emission reduction of greenhouse gas must be achieved in this century. In the COP21 of United Nations Framework Convention on Climate Change (UNFCCC) on December 2015 in Paris, a new mechanism of CO2 emission reduction (Paris Agreement) was adopted based on the pledge-and-review approach. Fusion energy...
Mr
Sergey Konovalov
(NRC "Kurchatov Institute")
21/10/2016, 08:30
THS - Magnetic Confinement Theory and Modelling: Stability
Poster
Substantial fraction of the plasma current can be converted into runaway electron (RE) current in ITER disruptions. During the RE plateau stage of the disruption the kinetic energy of a runaway beam is expected to be much smaller than the magnetic one. However, at the following current termination phase, the electric field induced due to the RE loss to the wall causes the generation of new and...
Mr
Gediminas Stankunas
(Lithuanian Energy Institute)
21/10/2016, 08:30
Activation inventories and decay heat are important nuclear quantities which need to be assessed on a reliable basis for fusion materials for the safe operation of a fusion nuclear power reactor and its final decommissioning. This comparative paper describes the activation and decay heat calculations for WCLL performed in the frame of the EUROfusion WPSAE programme and specifications in...
Prof.
Mikhail Rozenkevich
(D. Mendeleev University of Chemical Technology of Russia)
21/10/2016, 08:30
One of the most important tasks among initial tasks for realization of the project is to determine different types of the engineering systems which will be required to support of the engineering infrastructure of IGNITOR. One of the most important systems will be tritium fuel cycle and detritiation systems which provides scientific program of the investigation on IGNITOR tokamak. This work...
Dr
GUSTAVO GRANUCCI
(IFP - CNR)
21/10/2016, 08:30
For the development of a DEMOnstration Fusion Power Plant the design of auxiliary heating systems is a key activity to achieve a controlled burning plasma. The present heating mix considers Electron Cyclotron Resonance Heating (ECRH), Neutral Beam Injection (NBI) and Ion Cyclotron Resonance Heating (ICRH) with a target power to the plasma of about 50 MW for each system. The main tasks assigned...
Prof.
Piergiorgio Sonato
(consorzio RFX)
21/10/2016, 08:30
In the framework of the EUROfusion Work Package Heating & Current Drive, a conceptual design of the Neutral Beam Injector (NBI) for DEMO, has been developed by Consorzio RFX in collaboration with other European institutes. High efficiency is a fundamental requirement for DEMO, this has been taken into great consideration for the DEMO NBI, as a fundamental part of the maximization of RAMI...
Dr
Daniel López-Bruna
(CIEMAT)
21/10/2016, 08:30
Magneto-hydrodynamic (MHD) activity is ubiquitous in magnetic confinement plasmas and is related with confinement states. Particularly, confinement quality in TJ-II plasmas is intimately linked to the location and behaviour of magnetic resonances in the plasma column, which often manifest themselves as magnetic islands. Two main physical processes have been identified that relate confinement...
Dr
Jan Stockel
(Institute of Plasma Physics, AS CR)
21/10/2016, 08:30
Small magnetic fusion devices continue to contribute to many areas of fusion research because of their compactness, flexibility, low operation costs and the high skill of their personnel. The concept of interactive co-ordinated joint research using small devices in the scope of IAEA Co-ordinated Research Projects (CRP) was started in 2004 with as overall objective to contribute to streamlining...
Prof.
David Maurer
(Auburn University)
21/10/2016, 08:30
The control of sawtooth oscillations is currently an active area of tokamak research. Large sawtooth oscillations need to be avoided in ITER, since these large sawteeth couple to neoclassical tearing modes and edge localized modes resulting in serious confinement degradation. Small sawtooth oscillations, however, may be beneficial in preventing impurity and helium ash accumulation in the...
Prof.
Xueyu Gong
(University of South China)
21/10/2016, 08:30
The current driven by combined electron cyclotron wave (ECW) and high harmonic fast wave (HHFW) is investigated with the GENRAY and CQL3D package. It is shown that no significant synergetic current is found in a range of cases with combined ECW and FW. This result is consistent with the former study [R.W. Harvey, et al., in Proceedings of IAEA TCM on Fast Wave Current Drive in Reactor Scale...
Weixing Ding
(University of California Los Angeles, California 90095, USA)
21/10/2016, 08:30
Plasma confinement and sustainment of a steady-state tokamak reactor depend on current density profile control to manage MHD instabilities. A number of operational scenarios have been identified for high-performance and high-beta tokamak operation. In these high-temperature plasmas, current transport may occur on time scales much faster than resistive diffusion. Anomalous current transport...
Dr
sergey ananyev
(nrc Kurchatov institute)
21/10/2016, 08:30
As a part of the nuclear energy Research Center "Kurchatov Institute" development a program of creating a hybrid reactor combining nuclear and thermonuclear technologies was developed and proposed. The basis of a thermonuclear fusion reactor is neutron source (FNS) based on the tokamak [1]. The main difference from the FNS DEMO demonstration fusion reactor is that FNS is not necessary to...
Dr
Cedric Reux
(CEA, IRFM, F-13108 Saint Paul-lez-Durance, France.)
21/10/2016, 08:30
A demonstration power plant is the next step for fusion energy following ITER. The design of such reactors is currently ongoing and still requires solving a number of issues regarding the models used for the different subsystems of the plant. System codes are able to address these questions as they model every major element of the fusion power plant and their interactions. This ensures that...
Dr
Giovanni Grossetti
(DeITKarl)
21/10/2016, 08:30
The Power Plant Physics and Technology department (PPPT), being part of the EUROfusion Consortium established in 2014 and composed by European Fusion Laboratories (EFL), aims to develop a conceptual design for the Fusion DEMOnstration Power Plant.
With respect to present experimental machines and ITER, the main goals of DEMO are to produce electricity continuously for a period of 2 to 4...
Dr
Santanu Banerjee
(Institute for Plasma Research)
21/10/2016, 08:30
SST-1 [1] is a medium sized tokamak with a minor radius of 0.2m, magnetic field of 1.5T and is equipped with heating hydrogen neutral beam capable of delivering 0.5 - 1.7 MW with a variable beam energy of 30-55 keV [2]. The beam parameters provide good candidate for CXRS on SST-1. Using this neutral beam, Charge Exchange Recombination Spectroscopy (CXRS) [3, 4] is proposed for SST-1 Tokamak to...
Dr
Giacomo Aiello
(CEA Saclay)
21/10/2016, 08:30
The Helium Cooled Lithium Lead (HCLL) blanket concept is based on the use of Helium as coolant and the eutectic Pb-16Li as neutron multiplier and breeder material. This concept was originally developed in CEA at the beginning of 2000: it is one of the two EU blanket concepts to be tested in ITER in the form of a Test Blanket Module (TBM) and one of the four blanket concepts currently being...
Mr
Thomas Brown
(Princeton Plasma Physics Laboratory)
21/10/2016, 08:30
A Fusion Nuclear Science Facility (FNSF) study based on the Spherical Tokamak (ST) confinement option has progressed through a number of stages of development to understand the requirements to establish a self-consistent conceptual design of an ST-FNSF device. The objective has been to establish sufficient physics and engineering details needed to meet mission objectives centered on achieving...
Dr
rustam khayrutdinov
(NRC Kurchatov Institute)
21/10/2016, 08:30
In the present study a method of developing a magnetic control system of the plasma parameters (position, form, current) of the modernized now tokamak T-15 is described. According to the identification of the electromagnetic system and the plasma column of T-15 linear models are built for obtaining control regulators of the two types: 1) proportional-differential regulator to control of plasma...
Dr
NOBUYUKI AIBA
(Japan Atomic Energy Agency)
21/10/2016, 08:30
THS - Magnetic Confinement Theory and Modelling: Stability
Poster
Diamagnetic MHD equations for plasmas with fast flow were derived for the first time by introducing a suitable ordering parameter to two fluid equations. The extended Frieman-Rotenberg (F-R) equation was obtained from the diamagnetic MHD equations by focusing on impacts of the ion diamagnetic drift effect on ideal MHD stability in rotating plasmas. The MINERVA-DI code was developed to solve...
Mr
Min Xu
(Southwestern Institute of Physics)
21/10/2016, 08:30
Turbulent momentum flux, including the Reynolds stress, convective flux, and the flux driven by nonlinear interactions, was experimentally measured in ELMy H-mode. And it was found that net momentum in the electron diamagnetic direction was injected from the edge into the plasma during ELMs. This is a direct evidence that plasma is able to serve as a heat engine to convert heat into poloidal...
Dr
Emmanuel Joffrin
(CEA)
21/10/2016, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
Disruption remains the major risk for the operation of ITER and fusion reactors. JET is now equipped with three fast disruption mitigation valves (DMVs) located at different poloidal and toroidal locations mimicking the ITER set-up of DMVs. In JET, massive gas injection (MGI) from one DMV is systematically applied with 90% deuterium and 10% Argon when a disruption event is detected for plasma...
Prof.
Gunsu YUN
(Pohang University of Science and Technology)
21/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Edge-localized modes (ELMs) in the KSTAR tokamak appear substantially different from the conventional picture of ELMs as an explosive transport event in the plasma edge triggered by exponentially growing ballooning and external kink modes on the low field side of the plasma. The 2-D images of ELMs visualized by an advanced imaging diagnostics^1 with microsecond time resolution revealed that...
Dr
Lei Xue
(Southwestern Institute of Physics)
21/10/2016, 08:30
THS - Magnetic Confinement Theory and Modelling: Stability
Poster
The medium-sized copper-conductor tokamak HL-2M, is currently under construction and to be put into operation in the near future. The (up-down) symmetric poloidal field coil system inside the toroidal field coils of the machine has the capability of generating high vertically-elongated plasma. Thus the VDE is an unavoidable issue for HL-2M. Meanwhile, the opposite PF current in the middle of...
Dr
Sergey Lashkul
(Ioffe Institute)
21/10/2016, 08:30
To explain a relatively good efficiency of LHCD and improved core confinement transition obtained at the small FT-2 tokamak ($R=0.55m$, $a=0.08m$, $B_T \le 3T$, $I_{pl} = 35 kA$, f_0 = 920МHz, Δt_pl = 50ms, Δt_RF = from 30ms to 36ms) [1] a thorough modeling of experimental data has been performed. Effect of LHW on the transition into improved core confinement regime is discussed in the...
Dr
Alessandro Bortolon
(PPPL)
21/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
DIII-D studies of high-frequency ELM pacing by pellet injection were extended to ITER scenarios at low beam torque, demonstrating ELM peak heat flux mitigation with D2 pellets, and also with Li spheres, proving the concept of ELM pacing with non fuel pellets, a technique that could potentially reduce the throughput to the pumping and fuel reprocessing systems in ITER.
Injection of D2 pellets...
Dr
Guosheng Xu
(Institute of Plasma Physics, Chinese Academy of Sciences)
21/10/2016, 08:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
A new control technique for the edge-localized modes (ELMs) by pace-making with low-hybrid current drive (LHCD) power modulation has been demonstrated, for the first time, in the EAST superconducting tokamak. The achievable pace-making frequency is up to 120Hz, which appears to be limited only by the pedestal recovery time. LHCD leads to the density pump-out and local flattening of the density...
Dr
Robert Lunsford
(Princeton Plasma Physics Laboratory)
21/10/2016, 08:30
We report on ELM triggering and pacing experiments in NSTX-U, including comparisons to pellet ablation models. Multiple sizes and types of solid impurity granules are injected into the low field side of the plasma to determine their ELM triggering and pacing capability. Examining the penetration depths, mass deposition locations, and ELM triggering efficiencies of sub-millimeter lithium,...
Dr
Youwen Sun
(Institute of Plasma Physics, Chinese Academy of Scienses)
21/10/2016, 08:30
A big progress has been made in the type-I Edge Localized Mode (ELM) control with Resonant Magnetic Perturbation (RMP) on EAST in 2014 and 2015. A flexible in-vessel RMP coil system has been installed in 2014 for active MHD instabilities control to achieve long pulse steady state operation in the EAST tokamak. It can generate a variety range of spectrum covering most important...
Prof.
Minh Quang Tran
(EPFL -CRPP)
21/10/2016, 08:30
In the frame of the European Fusion Roadmap and under the Power Plant Physics and Technology program, the EUROfusion Consortium is conducting detailed studies on a tokamak DEMOnstration power plant. Scoping studies (e.g. scanning the aspect ratios and the toroidal magnetic field) are being performed. The EU DEMO1-2015 baseline is a 5. 7 T reactor delivering electricity in long pulse (> 2...
Dr
Liang Wang
(Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP))
21/10/2016, 08:30
Active control of high heat and particle fluxes deposited on the divertor targets is an essential issue for steady-state operations on the experimental advanced superconducting tokamak (EAST) and other future fusion devices, such as ITER. The change of edge magnetic topology is an effective method to exert positive influence on divertor heat and particle fluxes, which has been achieved by...
Dr
Hogun Jhang
(National Fusion Research Institute)
21/10/2016, 08:30
THS - Magnetic Confinement Theory and Modelling: Stability
Poster
We study the role of zonal flows in edge pedestal collapse using a reduced magnetohydrodynamic (MHD) model. A dramatic change of dynamics happens when ideal ballooning modes are stabilized. A detailed analysis shows that a zonal flow driven instability is developed due to a strong excitation of zonal vorticity, resulting in secondary crashes. The presence of subsidiary bursts after a main...
Mr
Min Xu
(Southwestern Institute of Physics)
21/10/2016, 08:30
Sheath potential coefficient α is a very important parameter in Langmuir probe measurement. It is often used to estimate the plasma potential: Vp=Vf+αTe, where Vf and Te are floating potential and electron temperature respectively.In magnetized high temperature fusion plasmas this coefficient is affected by many factors and may lead to large errors in the inferred electric field and fluid...
Dr
Xiaoquan JI
(Southwestern Institute of Physics, Chengdu 610041 China)
21/10/2016, 08:30
We present the first experimental observation of self-regulation of nonlocal transport events by NTMs generated during transient nonlocal transport events. The nonlocal effect is excited by edge cooling and propagates inward by avalanche events. These cause a local increase of the pressure gradient at the inversion surface, and thus the onset of the NTM in relatively low β plasmas. The...
Dr
Bo Lyu
(Institute of Plasma Physics, Chinese Academy of Sciences)
21/10/2016, 08:30
Rotation driven by radio-frequency waves have been studied on EAST for plasmas heated by LHW, ICRF and ECRH. Understanding of momentum transport characteristics plays an important role in pushing towards RF-heating dominated high-performance plasma operations on EAST. Using newly developed diagnostics, studies on RF-heated plasma rotation and momentum transports have been further carried out....
Prof.
MASAYUKI YOKOYAMA
(National Institute for Fusion Science)
21/10/2016, 08:30
The integrated transport analysis suite, TASK3D-a (Analysis), has been developed to be capable for routine whole-discharge analyses of plasmas confined in three-dimensional (3D) magnetic configuration such as the LHD.
The routine dynamic energy balance analysis for NBI-heated plasmas was made possible in the first version released in September 2012, which consisted of four parts: LHD data...
Dr
Shinsuke Fujioka
(Institute of Laser Engineering, Osaka University)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
Here we report recent experimental results relevant to the fast ignition (FI) inertial confinement fusion assisted with external kilo-tesla magnetic field. We have experimentally observed generation of 0.6 kT of magnetic field by using laser-driven capacitor-coil scheme, short diffusion time (<< 1 ns) of laser-generated magnetic field into a target material, reduction of the REB beam diameter...
Dr
Annika Ekedahl
(CEA, IRFM)
21/10/2016, 08:30
The passive-active multijunction (PAM), a relevant lower hybrid current drive (LHCD) launcher design, was developed in view of a LHCD system for the second phase of ITER [1]. PAM launchers have so far been successfully tested in L-mode plasmas on FTU [2] and Tore Supra [3]. This paper presents the first ever experiments with a PAM on H-mode plasmas, carried out on HL-2A tokamak [4] as a joint...
Dr
Xiaodong ZHANG
(CnIPPCAS)
21/10/2016, 08:30
A new divertor concept, the Fishtail divertor (FTD), is proposed and investigated on EAST, which can quickly move the strike point along the radial and poloidal direction like the swing of fishtail by additional alternating magnetic field. The maximum moving distance of the strike point is controlled by the alternating field amplitude. The wetted area of the heat flux is widened, so that the...
Prof.
satoshi konishi
(Kyoto University)
21/10/2016, 08:30
This paper points out one of the critical issue overlooked for fusion to become a viable energy source in the future, quantitatively analyzes the requirements, and suggests a possible solution. Future grids in possible markets and the impact of fusion introduction was analyzed with numerical model, and the limitation and requirements of the generation capacity of fusion plant is shown as the...
Dr
Xinjun Zhang
(Institute of Plasma Physics Chinese Academy of Sciences (ASIPP))
21/10/2016, 08:30
The paper summarizes the recent experiments performed with Ion Cyclotron Resonance Heating(ICRH) on EAST. Heating and confinement studies using the Hydrogen Minority Heating scheme have been investigated in Ohmic target plasma and in combination with Low Hybrid waves. Energy Confinement follows Scaling Law. The results show a typical L-mode behavior, i.e. a power dependent confinement...
Prof.
Nagato Yanagi
(National Institute for Fusion Science)
21/10/2016, 08:30
There is considerable progress in conceptual design studies of the helical fusion reactor FFHR-d1. The continuously wound helical coils (major radius 15.6 m) employ the 100-kA-class HTS (high-temperature superconducting) STARS (Stacked Tapes Assembled in Rigid Structure) conductor using a simple-stacking technique of YBCO tapes. A prototype STARS conductor reached 100 kA at 5.3 T and 20 K. A...
Dr
Sergei Lebedev
(Ioffe Physical-Technical Institute, Russian Academy of Sciences)
21/10/2016, 08:30
Bursts of high frequency oscillations have been found in Ohmically heated plasmas in the TUMAN-3M using magnetic probes sited inside vacuum vessel. Typical frequencies of the oscillations are within 0.8-1.8 MHz range. It was found that the frequency of the oscillations followed the dependence of Alfven velocity on toroidal magnetic field and density. This dependence allowed identifying the...
Dr
Marco Ferrari
(Fusion for Energy)
21/10/2016, 08:30
The Test Blanket Module (TBM) Program in ITER provides breeder units and related systems with all relevant technologies to test and validate design concepts of tritium breeding blankets for a power-producing reactor, specifically DEMO. Three ports are allocated to the ITER Members (IM’s) participating to the TBM Program and 6 Test Blanket Systems (TBS) are going to be installed and tested...
Ms
Jyoti Agarwal
(Institute for Plasma Research)
21/10/2016, 08:30
Fusion community worldwide is looking forward to an efficient pellet injection system catering to the requirements of fueling high temperature and high density plasma. Various DEMO reactor design world over portray importance underling development of this technology. The important characteristics being looked forward are operational flexibility, high reliability and remote operation with...
Dr
Felix Warmer
(Max Planck Institute for Plasma Physics)
21/10/2016, 08:30
One of the high-level missions of the European Roadmap for the realisation of fusion energy is to bring the helical-axis advanced stellarator line (HELIAS) to maturity. The near-term focus is the scientific exploitation of the Wendelstein 7-X experiment in order to assess stellarator optimization in view of economic operation of a stellarator fusion power plant.
Meanwhile, the understanding...
Prof.
Yuhong Xu
(Southwestern Institute of Physics)
21/10/2016, 08:30
“Blob-filaments”, or simply “blobs”, denote radial convection of coherent plasma structures, which transport plasma mass and energy across the open magnetic field line region known as the scrape-off-layer (SOL) and enhance the plasma interaction with the surrounding material boundaries. The generation mechanism for blobs has been investigated for many years. Experiments and...
Mr
A Bader
(Max-Planck-Institute for Plasma Physics)
21/10/2016, 08:30
The paper summarizes the studies carried out on the use of an Ion Cyclotron Range of Frequency System on DEMO in the framework of the PPPT.
An ion cyclotron range of frequency (ICRF) heating system can contribute significantly to various plasma phases during an experimental cycle (‘shot’). It can be used in the plasma start‐up and current ramp-up phase, where election heating is...
Hans Rinderknecht
(Lawrence Livermore National Laboratory)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
Implosions of thin-shell capsules produce strongly-shocked (M > 10), low-density (ρ ~ 1 mg/cc), high-temperature (Ti ~ keV) plasmas, comparable to those produced in the strongly-shocked DT-vapor in inertial confinement fusion (ICF) experiments. A series of thin-glass targets was filled with mixtures of deuterium and Helium-3 gas ranging from 20% to 100% deuterium and imploded on the OMEGA...
Prof.
Xiang Gao
(Institute of Plasma Physics, Chinese Academy of Sciences)
21/10/2016, 08:30
The ITER baseline scenario of the standard H-mode operation (beta-N = 1.8) will be mainly sustained by inductive plasma current drive with the limited pulse duration. Two advanced scenarios of the hybrid scenario (beta-N = 2 ~ 2.5) and steady-state scenario (beta-N > 2.6) are being developed towards long pulse operation in present tokamak devices. A pulse duration of 32 s (about 20R, where R...
Prof.
Akifumi Yogo
(Institute of Laser Engineering, Osasa University)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
Fusion fast ignition assisted by laser-driven ion beams requires 10 kJ energy deposition onto the fuel core having ~500 g/cm^3 densities. Assuming 100 kJ as a technically manageable energy of the driving laser, the first milestone can be found on 10% conversion efficiency from the laser energy into ions having kinetic energies of 10-30 MeV/u.
In this paper, we experimentally investigate the...
Prof.
Junji Kawanaka
(Institute of Laser Engineering, Osaka University)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
A new heating laser for fast ignition, called the LFEX-Laser, has been demonstrated with all four beams. The obtained total pulse energy was 2 kJ for a 1 ps pulse duration. The peak power of 2 PW is the highest of all kilojoule lasers in the world and was achieved with a high intensity contrast ratio of 1 × 10^10. To increase the pulse energy to the kilojoule class in a short pulse of 1–2 ps,...
Prof.
Yi Liu
(southwestern institute of physics)
21/10/2016, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
Disruption mitigation experiments with MGI have been carried out on HL-2A with a rapid (~1 ms), massive (~1021 particles) injection of helium/neon/argon to study various injection scenarios. The behaviors of runaway currents in MGI induced disruptions have been investigated. A long-lasting RE plateau is achieved after argon injection by MGI even at Bt = 1.28 T, much lower than previous Bt...
Prof.
Chijin Xiao
(University of Saskatchewan)
21/10/2016, 08:30
Plasma flow and its shear in tokamak discharges have many beneficial effects including suppression of turbulence, confinement improvement, control of the resistive wall modes, as well as enhanced tolerance to the error fields which may cause mode locking and even major disruptions. CT injection has also been considered not only as a candidate to directly fuel the core of a tokamak reactor, but...
Dr
Stanislas Pamela
(CCFE - UKAEA)
21/10/2016, 08:30
THS - Magnetic Confinement Theory and Modelling: Stability
Poster
Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicated pedestal models like EPED, and from non-linear MHD codes like...
Mrs
Marta Velarde
(Institute of Nuclear Fusion, UPM-Spain)
21/10/2016, 08:30
Tritium leakages are a major concern regarding nuclear power plants, not only in commercial fission power plants, but also in future fusion power plants. Future fusion reactors, as for example those being studied in the ITER and NIF experiments, will breed tritium from other elements to use it as fuel. Hence, the need for preventing and containing tritium leakages, as it is done with any other...
Dr
Paul Bonoli
(Plasma Science and Fusion Center - MIT)
21/10/2016, 08:30
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Oral
High field side (HFS) launch of RF power in the ion cyclotron range of frequencies (ICRF) and the lower hybrid range of frequencies (LHRF) in double null configurations in reactor grade plasmas is studied and found to represent an integrated solution that both mitigates PMI / coupling problems and at the same time opens up the possibilities of greatly improved core wave physics
Power...
Dr
Roger Raman
(University of Washington)
21/10/2016, 08:30
Predicting and controlling disruptions is an important and urgent issue for ITER. In support of this activity, NSTX-U will employ three Massive Gas Injection (MGI) valves that are similar to the double flyer plate design being developed for ITER [1]. NSTX-U will be the first device to operate this valve configuration in plasma discharges. NSTX-U experiments will offer new insight to the MGI...
Mr
JongSung Park
(National Fusion Research Institute (NFRI))
21/10/2016, 08:30
Studies to investigate the feasibility of the divertor system have been proceeding since the pre-conceptual design study on the Korean fusion demonstration reactor (K-DEMO) was initiated in 2012. The divertor is one of the main components and biggest challenges for a tokamak reactor. Its major function is the emission of the heat flux, helium and impurities from the plasma, and also the...
Mr
Chandan Danani
(Institute for Plasma Research, Bhat, Gandhinagar , Gujarat, India-382428)
21/10/2016, 08:30
SST-2 will be a medium size Indian fusion reactor to be built for realizing the reactor technologies and D-T fuel cycle. It has a low fusion gain (Q = 5) and fusion power output can be from 100 to 300 MW. This work presents nuclear design analyses for SST-2 employing the Indian LLCB (Lead Lithium Ceramic Breeder) blanket for the tritium breeding. The nuclear design analyses address the...
Dr
Johan Frenje
(Massachusetts Institute of Technology)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
Hot-spot ignition planned at the National Ignition Facility (NIF) requires proper assembly of the DT fuel, as manifested by the evolution of areal density (ρR) symmetry and hot-spot ion temperature (Ti). Ideally, a spherically symmetric layer of cold and dense fuel with a ρR exceeding 1 g/cm2 surrounding a ~5 keV lower-density hot spot is obtained at peak convergence. To reach these...
Dr
Carlos Hidalgo
(CIEMAT, Spain)
21/10/2016, 08:30
In the present paper we have investigated the influence of ECRH on neoclassical and anomalous mechanisms in the TJ-II stellarator. The results reported here were obtained by the use of a unique diagnostic which consists in two Heavy Ion Beam Probe (HIBP) systems located at two different toroidal ports separated by 900. This dual HIBP was used to study the temporal and spatial evolution of...
Mr
Zengyu Xu
(Southwestern Institute of Physics)
21/10/2016, 08:30
FNS - Fusion Nuclear Physics and Technology
Poster
After obtaining a full-coverage free curve-surface flow by curve plate with three layer meshes, new experimental results showed that a full-coverage free surface flow can’t be obtained by a flat plate with meshes. More were recently investigated on MHD effects of other free surface flows flowing on flat plate. Base on the experimental data and newly developed modeling method, other way is...
Prof.
Mikhail Gryaznevich
(Tokamak Energy Ltd)
21/10/2016, 08:30
Recent advances in the development of high temperature superconductors (HTS) and encouraging results on a favourable dependence of confinement on increase in toroidal field (TF) in Spherical Tokamaks (ST) open new prospects for a high field ST as a compact fusion reactor or a powerful neutron source [1]. The combination of the high beta(ratio of the plasma pressure to magnetic pressure),...
Dr
Anna Widdowson
(UKAEA)
21/10/2016, 08:30
Post mortem analysis of components removed from the JET ITER-like wall (JET-ILW) provides an overall picture of long term fuel inventory. Results from the first 2011-12 (ILW-1) and second 2013-14 (ILW-2) JET-ILW campaigns are now available making a comprehensive overview possible. Overall plasma times for ILW-1 and ILW-2 are similar: ~ 6 hours limiter plasma and ~14 / ~13 hours divertor...
Mr
ABHISHEK SARASWAT
(InIPR)
21/10/2016, 08:30
The Lead-Lithium Ceramic Breeder Test Blanket Module (LLCB-TBM) is the Indian TBM representing the DEMO breeding blanket, to be installed in ITER radial port no-2. The prime testing objective of LLCB TBM in ITER is to generate experimental data on the performance of tritium breeding blankets (such as tritium breeding and its extraction, nuclear heat extraction, neutron shielding) in an...
Dr
Jean-Luc Miquel
(CEA)
21/10/2016, 08:30
IFE - Inertial Fusion Experiments and Theory
Poster
Since the operational commissioning of the Laser Megajoule (LMJ) in October 2014, several experimental campaigns have been achieved, with the first eight beams, and demonstrated LMJ’s aptitudes for the Simulation Program. The Simulation Program of the Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA) combines improvement of physics models, high performance numerical...
Prof.
G. -N. Luo
(CnIPPCAS)
21/10/2016, 08:30
The first EAST plasma was ignited in 2006 with non-actively-cooled steel plates as plasma-facing materials and components (PFMC) which was then upgraded into full graphite tiles bolted onto water-cooled copper heat sinks in 2008. And the first wall was changed further into TZM in 2012, while keeping graphite for both of the upper and lower divertors. With rapid increase in H&CD power in EAST,...
Mr
Nobuyuki Asakura
(Japan Atomic Energy Agency)
21/10/2016, 08:30
Handling of a large exhausted power to the SOL and divertor is the most important issue for DEMO reactor design. The plasma concept (Ip = 14 MA, R = 8.5 m, a = 2.5 m) with the reduced fusion power of 1.5 GW and central solenoid coils sufficient for inductive start was proposed. Plasma simulation of the power exhaust and engineering design of tungsten (W) plasma-facing-component and...
Dr
Kieran Joseph McCarthy
(Laboratorio Nacional de Fusion, Ciemat)
21/10/2016, 08:30
Core plasma fuelling is a critical issue on the pathway to developing steady-state scenarios in 3-dimensional magnetically confined plasma devices. Indeed, neoclassical theory predicts that on-axis electron cyclotron resonance heating (ECRH) requires a particle source situated at the same radial position as ECRH with an analogous deposition profile shape in order to mitigate potential core...
Dr
Teresa Estrada
(CIEMAT)
21/10/2016, 08:30
The effect of magnetic islands on plasma flow and turbulence is experimentally investigated in ohmically induced magnetic configuration scans at TJ-II. This operational mode allows sweeping the radial position of a low order rational surface in a controlled way, what reveals effects that are difficult to notice in scans performed on a shot to shot basis. The main diagnostic used in the present...
Dr
Ronald Wenninger
(Max-Planck-Institut für Plasmaphysik)
21/10/2016, 08:30
The development of a conceptual design for a demonstration fusion power plant (DEMO) is a key priority of the recent European fusion program [1]. The DEMO design/R&D is expected to benefit largely from the experience gained with ITER construction and operation, but there are still outstanding gaps requiring a vigorous physics and technology R&D programme. The constraints coming from specific...
Dr
Guoqiang Li
(Institute of Plasma Physica, CAS)
21/10/2016, 08:30
The Chinese Fusion Engineering Test Reactor (CFETR) is under design. The machine aims to fill the gaps between ITER and DEMO. Recently, the physical design focuses on the so-called baseline scenario. It is a 10 MA steady state scenario to produce ~200 MW fusion power. With the integrated modelling of the equilibrium calculation, pedestal structures prediction, 1.5D core transport simulation,...
Dr
George Neilson
(Princeton Plasma Physics Laboratory)
21/10/2016, 08:30
A conceptual design study for a steady-state fusion demonstration reactor, K DEMO, has been undertaken by the National Fusion Research Institute (NFRI) in the Republic of Korea. Analyses of the plasma heating and current drive configuration and of the tokamak configuration have continued in support of the study. It is assumed that a combination from among at least the standard heating and...
Ms
Jyoti Agarwal
(Institute for Plasma Research)
21/10/2016, 08:30
The exhaust from a fusion grade machine comprises mainly isotopes of hydrogen gas and helium as the main content. The challenge lies in pumping voluminous amount of exhaust gases of the order of 200-400 Pa.m3/s. At present, pumping such a large throughput of gas in a perpetual way is a topic of primary focus in the field of vacuum science. Important requirement is of establishing technology at...
Dr
roger stoller
(oak ridge national laboratory)
21/10/2016, 08:30
In addition to the engineering challenges associated with building and operating any complex facility, a range of critical materials issues must be addressed in order to make fusion power commercially viable. These include: (1) developing structural materials with suitably long lifetimes, (2) obtaining a plasma-facing material with sufficient ductility and low tritium retention, and (3)...
Dr
B J Ding
(Institute of Plasma Physics, Chinese Academy of Science)
21/10/2016, 08:30
To explore lower hybrid current drive at reactor relevant, high density is an important issue. Collisional absorption (CA), parametric instabilities (PI) and scattering from density fluctuations (SDF) are considered as possible candidates for the current drive (CD) efficiency decreasing faster than theory prediction. A multi-machine assessment, including experiments and modeling in EAST, C-Mod...
David Schissel
(General Atomics)
21/10/2016, 08:30
Scientists at General Atomics (GA) have conducted in the United States remote experimental operation of the Experimental Advanced Superconducting Tokamak (EAST) in China during their third shift. These experiments were led by scientists in a dedicated remote control room that utilized a novel computer science hardware and software infrastructure to allow data movement, visualization, and...
Dr
Junichi Miyazawa
(National Institute for Fusion Science)
21/10/2016, 08:30
A new liquid metal divertor concept named the REVOLVER-D (Reactor-oriented Effectively VOLumetric VERtical Divertor) has been proposed for the helical fusion reactor FFHR-d1. The REVOLVER-D consists of molten tin shower jets stabilized by chains set inside each jets. These are installed in 10 inner ports of FFHR-d1 to intersect the ergodic layer surrounding the last-closed-flux-surface. The...
Dr
Zhongbing Shi
(Southwestern Institute of Physics)
21/10/2016, 08:30
In the next generation of large fusion device ITER, it has been accepted that the divertor could not endure the heat exhaust due to the edge localized modes (ELM), without any action to mitigate. The physical mechanism and controlling methods of ELM have become the important tasks in physics of boundary plasmas. The supersonic molecular beam injection (SMBI), one of numerous approaches to...
Prof.
Jiaqi Dong
(Southwestern Institute of Physics)
21/10/2016, 08:30
Detailed analyses of the dynamic evolutions of the pedestal, including density, temperature, pressure and their gradients were performed in recent H-mode experiments on HL-2A tokamak. Dramatic increase of density gradient and decrease of electron temperature gradient were observed in the pedestal just prior to each burst in a series of ELM eruptions. An inward particle flux inducing...
Dr
Gergely Papp
(Max Planck Institute for Plasma Physics)
21/10/2016, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
Disruptions in tokamaks can lead to the generation of a relativistic runaway electron (RE) beam that may cause serious damage to the first wall. The uncontrolled loss of such a high energy electron beam is intolerable and therefore the issue of how to avoid or mitigate the beam generation is of prime importance for ITER. The European medium sized tokamaks ASDEX Upgrade (AUG) and TCV have...
Mr
Alexander Shevelev
(RuIoffe)
21/10/2016, 08:30
Analysis of the super-thermal and runaway electrons behavior in ohmic and low-hybrid current drive FT-2 tokamak ($R=0.55m, a=0.08m, B_T≤3T, I_pl =32kA, \langle n\rangle = 1.9 \times 10^{19}m^{-3}, f_0=920МHz$) plasmas has been carried out using information obtained from measurements of hard X-ray spectra and non-thermal microwave synchrotron radiation intensity in the frequency range (53 ÷ 78)...
Dr
Youji Someya
(Japan Atomic Energy Agency)
21/10/2016, 08:30
This paper presents safety and waste management studies for a fusion DEMO reactor. It was found that an impact of a large-scale ex-vessel loss-of-coolant accident (LOCA), i.e., a guillotine rupture of a main pipe of the primary cooling system with pressurized water reactor (PWR) condition (320ºC, 16 MPa), can be mitigated by using a vault for the Tokamak Cooling Water System (TCWS) with a...
Mr
nicolas commaux
(oak ridge national laboratory)
21/10/2016, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
The shattered pellet injection (SPI) technique has demonstrated disruption thermal quench (TQ) and current quench (CQ) control that scale to meet ITER disruption mitigation requirements. This innovative technique was tested for the last few years on DIII-D and showed improved results when compared to massive gas injection (MGI) technique in comparable conditions. Major disruptions on large...
Prof.
Dennis Whyte
(MIT Plasma Science Fusion Center)
21/10/2016, 08:30
The recent industrial maturation of high-temperature, high-field superconductors opens up a faster and cheaper development path for fusion energy by enabling reactor-level performance at smaller scale. The current fusion energy development path, based on large volume moderate magnetic B field devices is proving to be slow and expensive. A development effort is underway on new superconductor...
Dr
FARAH DEEBA
(National Tokamak Fusion Program, Pakistan)
21/10/2016, 08:30
Optical emission spectroscopy is applied as a diagnostic tool to investigate the plasma in GLAST-III (glass spherical tokamak) at different scenarios. It is a small limiter device having aspect ratio (R/a = 2) with major radius R = 20 cm and minor radius a = 10 cm. Spectral analysis is performed to study the plasma induced optical emission and the electron temperature for different values of...
Dr
Vladimir Minaev
(Ioffe Institute, St. Petersburg, Russian Federation)
21/10/2016, 08:30
The Globus-M spherical tokamak has demonstrated practically all of the project objectives during the 15-year period of operation. The main factor limiting further enhancement of plasma parameters is a relatively low toroidal magnetic field. The increasing of the magnetic field up to 1.0 T together with the plasma current up to 0.5 MA will result in the significant extension of the operating...
Yuri Shpanskiy
(NRC "Kurchatov Institute")
21/10/2016, 08:30
FNS - Fusion Nuclear Physics and Technology
Poster
Fusion-fission hybrid facility based on superconducting tokamak DEMO-FNS is developed in Russia for integrated commissioning of steady-state and nuclear fusion technologies at the power level up to 40 MW for fusion and 400 MW for fission reactions. The project status corresponds to transition from conceptual design to engineering one. This facility is considered in RF as the main source of...
Dr
Petr Khvostenko
(NRC"Kurchatov Institute")
21/10/2016, 08:30
Presently, the Tokamak T-15MD is being built. The magnet system of the Tokamak T-15MD will obtain and confine the hot plasma in the divertor configuration. Plasma parameters are a major radius of 1.48 m, a minor radius of 0.67 m, an elongation of 1.7-1.9 and a triangularity of 0.3-0.4. Tokamak T-15MD will equipped with the auxiliary plasma heating and current drive (Paux =15 - 20 MW) systems....
Prof.
Artur Malaquias
(Instituto Superior Tecnico, Universidade de Lisboa)
21/10/2016, 08:30
It has been experimentally established in ISTTOK that edge electrode biasing under appropriated conditions improves confinement by reducing radial transport. In order to improve the repeatability and reproducibility of AC operation edge electrode biasing was used to assist the transition of plasma current applied at different time lapses of the AC discharge. This paper presents the results of...
Prof.
Zhengying Cui
(Southwestern Institute of Physics)
21/10/2016, 08:30
In next-generation fusion devices the reduction of impurity concentration in core plasmas is of great importance not only for the decrease in the line radiation loss but also for mitigation of the fuel dilution and the bremsstrahlung radiation to achieve high-performance plasmas in the high density regime. In experiments, the electron cyclotron resonance heating (ECRH) has been widely applied...
Dr
Subrata Pradhan
(Institute for Plasma Research)
21/10/2016, 08:30
The superconducting magnets system (SCMS) of the fusion devices e.g. tokamak / stellarator consists of complex superconducting magnetics. In order to supply such high currents from the power supplies to the SCMS, many numbers of current leads (CLs) are required in the range of 4.5 K – 300 K. As the studies revealed that based on the duty cycle of operation of fusion device, almost 25% - 30% of...
Mr
Eric Villedieu
(CEA-IRFM)
21/10/2016, 08:30
Fusion Tokamaks are complex machines which require special conditions for their operation, in particular, high vacuum inside the vessel and high temperature of the vessel walls. During plasma phases, the first wall components are highly stressed and the control of their surface is necessary in case of doubt about their condition. To be able to make safely such an inspection in a short period...
Dr
Jean-Claude Vallet
(CEA)
21/10/2016, 08:30
The CEA contributions to the Broader Approach projects, IFERC, IFMIF and JT-60SA which included the deliveries of components and services are now approaching completion. For IFERC, the supercomputer Helios, provided by CEA, will perform until the end 2016 its last runs after 5 years of operation close to its nominal capabilities. For IFMIF, the CEA contributions include the deliveries and the...
Mr
qiyong zhang
(Institute of plasma physics Chinese Academy of sciences)
21/10/2016, 08:30
Since the first commissioning in February 2006, EAST cryogenic system has been in operation for eleven plasma experiment campaigns with high reliability. However, ten years have passed from the beginning of the system operation. With requirements of EAST physical experiment, new users of cryogenic system have been added such as cryopump, pellet inject and NBI. Some upgrades have been...
Mr
Chandan Danani
(Institute for plasma research)
21/10/2016, 08:30
A key step towards a DEMO reactor and beyond is the development of key facilities addressing various engineering and physics issues. In the Indian plan, SST 2 is under consideration as a low Fusion gain (Q =5) Reactor for realizing and qualifying technologies for D-T fusion cycle and for the Indian DEMO programme [1][2]. The 0 D physics design of SST 2 is done using the 0 D systems code...
Dr
Gregory Wallace
(MIT Plasma Science and Fusion Center)
21/10/2016, 08:50
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
Experimental and modeling results from Alcator C-Mod and NSTX show that details of the scrape off layer (SOL) can significantly impact the effectiveness of radio frequency (RF) heating and current drive actuators. C-Mod experiments show that cold, dense conditions in the SOL lead to significant collisional absorption of lower hybrid (LH) waves outside the last closed flux surface (LCFS),...
Dr
Tetsutarou Oishi
(National Institute for Fusion Science)
21/10/2016, 09:10
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
Stochastization of edge magnetic fields has been extensively studied not only for the ELM mitigation but also for the plasma detachment and the impurity transport. Large Helical Device (LHD) has a thick stochastic magnetic field layer called “ergodic layer” located at the edge plasma with three-dimensional structure intrinsically formed by helical coils. Recently, reduction of the parallel...
Dr
Bernhard Sieglin
(Max-Planck-Institut for Plasma Physics)
21/10/2016, 09:30
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
A. Studies of the steady state scrape-off layer heat transport with and without external magnetic perturbation in ASDEX Upgrade L-Mode are shown. It is found that the heat transport perpendicular to the magnetic field is within the uncertainty unaffected by external magnetic perturbation. The observed heat flux pattern is explained by heat flux calculations using the vacuum field of the...
Dr
Nirmal Kumar Bisai
(Institute for Plasma Research, Bhat, Gandhinagar-382428, India)
21/10/2016, 09:50
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Oral
Role of neutral gas in Scrape-off Layer (SOL) of tokamak plasma is important as it modifies the
plasma turbulence. This has been investigated using a simple two-dimensional (2D) model that
consists of electron continuity, quasi-neutrality, electron energy and neutral gas continuity
equations. Earlier the role of the neutral gas has been studied using uniform electron
temperature [1]....
Dr
Maiko Yoshida
(Japan Atomic Energy Agency)
21/10/2016, 10:45
Negative magnetic shear has been demonstrated to mitigate the confinement degradation typically observed with increasing the electron to ion temperature ratio (Te/Ti), and the mechanisms are now understood in terms of fluctuation measurements and gyrokinetic (GK) simulations in DIII-D steady-state plasmas. The impact of Te/Ti on plasma transport and confinement is a critical issue for ITER and...
Dr
Christopher Holland
(University of California San Diego)
21/10/2016, 11:05
New experimentally validated simulations demonstrate for the first time that the turbulent transport that sets tokamak confinement is robustly multiscale across a variety of reactor-relevant regimes, with significant nonlinear cross-scale couplings that must be accurately described to correctly predict ITER performance. These gyrokinetic and gyrofluid simulations of electron transport...
Dr
Akihiro Ishizawa
(Kyoto University)
21/10/2016, 11:25
As a trial in evaluating helical system designed with different concepts, we have compared two devices, the Large Helical Device (LHD) and the Heliotron J (HJ), with different magnetic field structure under two key parameters, i.e. the Mercier/interchange measure D_well and the magnetic shear s_hat, focusing on their linear drift wave instability and nonlinear evolution leading to turbulent...
Dr
Jeronimo Garcia
(CEA IRFM)
21/10/2016, 11:45
The thermal energy confinement time has been observed to largely vary with the exchange of the main isotope in broad experimental conditions in magnetically confined plasmas, leading to the so called isotope effect. Of particular interest is the isotope exchange between the fusion of deuterium-deuterium (DD) and deuterium-tritium (DT) nuclei, studied in dedicated experiments performed in the...
Dr
TAKESHI IDO
(National Institute for Fusion Science)
21/10/2016, 14:00
Abrupt excitation of a geodesic acoustic mode (GAM) has been observed in the Large Helical Device (LHD), when the frequency of an up-chirping energetic-particle driven GAM (EGAM) approaches twice the ordinary GAM frequency. The abruptly exited GAM has larger amplitude and a lower frequency than the initially excited EGAM. The amplitude dependence of the growth rate of the abrupt GAM indicates...
Dr
Hiroyasu Tanigawa
(Japan Atomic Energy Agency)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
International Fusion Energy Research Centre (IFERC) has implemented DEMO research and development activities for 10 years under the Broader Approach (BA) activity. Five common issues on blanket technologies were selected and corresponding R&D has been carried out. The accomplishments of R&D were; successful production of reduced activation ferritc/martensitic steel in DEMO scale production...
Dr
Alfredo Portone
(Fusion For Energy)
21/10/2016, 14:00
In the design of next step tokamak devices, it will be of key importance to carefully optimize the plasma magnetic configuration, in particular its elongation, triangularity and aspect ratio. Indeed, the sharp dependence of the safety factor q upon plasma elongation and, as a consequence, of the maximum achievable plasma current in disruption-free operation mode is of paramount importance to...
Dr
Naoyuki Fukumoto
(University of Hyogo)
21/10/2016, 14:00
Compact toroid (CT) injection was conducted on several middle-class tokamaks in the previous experiments for development of an advance fueling method. We have carried out CT injection in a Spherical Tokamak (ST) plasma, for the first time, on QUEST equivalent to the tokamaks in facility size. The primary aim of the experiment is to produce a high-density ST plasma and control its density...
Dr
Joerg Stober
(IPP Garching)
21/10/2016, 14:00
Since 2007 the tokamak ASDEX Upgrade (AUG) successfully operates with fully W-coated
plasma facing components. Operation in this environment is facilitated using high levels of
deuterium puff to minimize W erosion of the out-board limiters by ELMs and by seeding impurities
in order to control divertor temperature at a low level to protect especially the W-coatings
of graphite tiles. These...
Dr
Tatsuya Kobayashi
(National Institute for Fusion Science)
21/10/2016, 14:00
Recent studies have indicated that the local theory of the electron heat transport cannot model the plasma response against the modulation electron cyclotron resonance heating (MECH) correctly. In this paper we propose a new method to analyze the MECH experiment, aiming to examine the local transport model. The method is applied to the MECH experiments performed in the helical (LHD and TJ- II)...
Dr
Daniele Carnevale
(Universita' Roma Tor Vergata, Dipartimento di Ing. Civile ed Ing. Informatica)
21/10/2016, 14:00
The challenging task for a disruption mitigation system (DMS) is the implementation of reliable strategies in order to mitigate thermal, mechanical and electromagnetic loads at disruptions. Furthermore, the DMS has to cope with control and suppression of runaway electron beams, which are possibly generated during major disruptions, in order to avoid localized high-energy deposition causing...
Dr
Yusuke Shibama
(Japan Atomic Energy Agency)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
The JT-60SA (JT-60 Super Advanced) project is a combined project of Japan’s program for national use and the Japan-EU Satellite Tokamak Program collaboration between Japan and the EU fusion community. The main objectives are to demonstrate steady-state high-beta plasma and to support ITER through the optimization of ITER operation scenario. The JT-60SA tokamak device is designed as a...
Dr
Bernhard Sieglin
(Max-Planck-Institut for Plasma Physics)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Studies of the steady state scrape-off layer heat transport with and without external magnetic perturbation in ASDEX Upgrade L-Mode are shown.
It is found that the heat transport perpendicular to the magnetic field is within the uncertainty unaffected by external magnetic perturbation.
The observed heat flux pattern is explained by heat flux calculations using the vacuum field of the...
Prof.
Boris Breizman
(The University of Texas at Austin)
21/10/2016, 14:00
When plasmas have a sufficient number of energetic particles to induce instability, such as may occur in burning plasmas, it is important to have a reliable method of predicting the nature of the unstable state that will arise. Two extreme scenarios for the TAE frequency, $\omega_{TAE}$ arises: relatively steady oscillations at one extreme and chirping oscillations at the other extreme. For...
Prof.
Rajesh Srivastava
(Indian Institute of Technology (I.I.T.) Roorkee, India)
21/10/2016, 14:00
An improved collisional radiative (CR) model has been developed for hydrogen-cesium plasma for its application to the negative hydrogen ion sources where we used reliable cross sections. The required electron impact excitation cross-sections have been obtained using fully relativistic distorted wave theory for various fine-structure transitions from the ground as well as excited states. These...
Mr
Vladimir Kornev
(Ioffe Institute)
21/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Recent experiments on the TUMAN-3M compact tokamak were aimed at study of fast ion (FI) capture and confinement in co-current NBI heating scheme. Target plasma parameters in the experiments were as follows: R0 = 0.53 m, al = 0.22 m, BT ≤ 1 T, Ip ≤ 180 kA, ne ≤ 4•1019 m-3, Te(0) ≤0.7 keV, Ti ≤ 0.2 keV. Maximum output power of deuterium neutral beam Pinj = 700 kW. Measurement of 2.45 MeV DD...
Dr
Richard Kemp
(Culham Centre for Fusion Energy)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
Although the ultimate goal of most current fusion research is to build an economically attractive power plant, the present status of physics and technology does not provide the performance necessary to achieve this goal. Therefore, in order to model how such plants may operate and what their output might be, extrapolations must be made from existing experimental data and technology. However,...
Dr
Christopher Holland
(University of California San Diego)
21/10/2016, 14:00
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
New experimentally validated simulations demonstrate for the first time that the turbulent transport that sets tokamak confinement is robustly multiscale across a variety of reactor-relevant regimes, with significant nonlinear cross-scale couplings that must be accurately described to correctly predict ITER performance. These gyrokinetic and gyrofluid simulations of electron transport...
Dr
Orso Meneghini
(General Atomics)
21/10/2016, 14:00
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
Accurate predictions of fusion performance requires including the strong interplay that exists between core transport, pedestal structure, current profile and plasma equilibrium. An integrated modeling workflow capable of finding the steady-state self-consistent solution to this strongly coupled problem has been developed. The workflow, leverages first principles calculations and does not...
Dr
Takuya Goto
(National Institute for Fusion Science)
21/10/2016, 14:00
In a heliotron type system like LHD, compatibility between MHD stability and good confinement is recognized as one of the crucial issues. This paper reports the world’s first attempt of the close investigation of self-consistent solution of plasma operation scenario in view of MHD stability, anomalous transport, alpha energy loss and impurity effect in addition to MHD equilibrium and...
Mr
Jisung Kang
(Seoul National University)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
A systematic, self-consistent process to find the K-DEMO operation scenario has been investigated. Recent progress on K-DEMO scenario study explored zero-dimensional operation regime and one-dimensional current density configurations with fixed safety factor profile [1]. However, previous researches do not contain confinement optimization process for stable equilibria. In this study, an...
Prof.
Aleksandr Burdakov
(Budker Institute of Nuclear Physics)
21/10/2016, 14:00
In 2015, the existing GOL-3 multiple-mirror trap has been converted into three specialized devices, each dedicated to a specific scientific problem. Experiments on studies of plasma mechanisms of sub-THz radiation generation use the GOL-3T device. A device with a sub-ms electron beam was isolated for further studies of ITER-grade transient heat loads to tungsten. Research of multiple-mirror...
Mr
David DOUAI
(CEA, IRFM, Association Euratom-CEA, 13108 St Paul lez Durance, France)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Wall conditioning will be required in JT-60SA to control fuel and impurity recycling and to improve plasma performance and reproducibility. In addition to glow discharge cleaning, operable only in the absence of toroidal field, Electron Cyclotron Wall Conditioning (ECWC) plasmas created with its ECRF launchers are envisioned. ECWC has been successfully operated in Helium at the first harmonic...
Prof.
Hidetoshi Hashizume
(Tohoku University)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
This study addresses development of mechanical joints and a heat removable technique for the remountable HTS magnet. We carried out (i) Optimizing structure and fabrication procedure of mechanical joints, and (ii) Analyzing heat transfer performance of metal porous media inserted channel to be applied to thermal analysis of joint. The developments and discussion will be taken into account in...
Dr
Emmanuel Joffrin
(CEA)
21/10/2016, 14:00
Disruption remains the major risk for the operation of ITER and fusion reactors. JET
is now equipped with three fast disruption mitigation valves (DMVs) located at different
poloidal and toroidal locations mimicking the ITER set-up of DMVs. In JET, massive gas
injection (MGI) from one DMV is systematically applied with 90% deuterium and 10%
Argon when a disruption event is detected for...
Dr
Petr Savrukhin
(NRC Kurchatov Institute)
21/10/2016, 14:00
Experiments in the T-10 tokamak (R=1.5m, a=0.3m) have demonstrated possibility of control of the plasma current decay and prevention of formation of the non-thermal (Eg>150keV) electron beams after an energy quench at the density limit disruption using electron cyclotron heating (ECRH) and pre-programmed Ohmic (OH) power supply system. Quasi-stable plasma operation with repetitive sawtooth...
Dr
Cristian Galperti
(Ecole Polytechnique Fédérale de Lausanne (EPFL), SPC, CH-1015 Lausanne, Switzerland)
21/10/2016, 14:00
A key feature of the new digital plasma control system installed on the TCV tokamak is its possibility to rapidly design, test and deploy real-time algorithms. It accommodates hundreds of diagnostic inputs and actuator outputs, and offers the possibility to design advanced control algorithms with better knowledge of the plasma state and to coherently control all TCV actuators, including...
Dr
YURI IGITKHANOV
(KIT)
21/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
One of the important tasks of the DEMO divertor design optimization is to ensure a desirable divertor performance and high pumping efficiency by varying, for example, the divertor dome height and pumping port position. In this paper we analyse the latest European DEMO divertor design with the pumping port located at the bottom of the divertor plenum. Optimization of the dome height and its...
Dr
Jeronimo Garcia
(CEA IRFM)
21/10/2016, 14:00
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
The thermal energy confinement time has been observed to largely vary with the exchange of the main isotope in broad experimental conditions in magnetically confined plasmas, leading to the so called isotope effect. Of particular interest is the isotope exchange between the fusion of deuterium-deuterium (DD) and deuterium-tritium (DT) nuclei, studied in dedicated experiments performed in the...
Prof.
Michael Probst
(University of Innsbruck)
21/10/2016, 14:00
Electron-impact cross sections yield the probability of an electron reacting with a particle – a molecule, an ion or an atom – as a function of the energy of that electron.
At low energies so-called dissociative electron attachment (DEA) is the predominant reaction mechanism.
At energies of the incoming electron higher than the ionization threshold of the particle, typically the particle...
Dr
Alexis Briesemeister
(ORNL)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
In DIII-D, measurements show that at high densities, above the onset of divertor detachment, the non-axisymmetric heat flux striations between ELMs created by resonant magnetic perturbation (RMP) fields are eliminated and the heat flux profile is nearly identical to that measured without RMPs. Measurements show that the RMPs continue to affect the particle balance even when there were no...
Dr
Onofrio Tudisco
(ENEA)
21/10/2016, 14:00
Here is reported the simulation of density evolution in discharges performed at Frascati Tokamak Upgrade (FTU) where a thermo-diffusion term have been used instead of the particle pinch. In these discharges a sensible density peaking is observed at high density, subsequent the formation of a strong MARFE thermal instability at plasma edge. They have been obtained in an experimental campaign...
Prof.
Byron Peterson
(National Institute for Fusion Science)
21/10/2016, 14:00
Various noble gasses have been seeded in the Large Helical Device (LHD) to reduce the divertor heat load through enhanced radiation [1]. At the vertically elongated cross-section, in the case of N_2 seeding, bolometric images show additional outboard radiation, while in the case of Ne, only inboard radiation is observed. With N_2 seeding, radiation is observed by two imaging bolometers [2],...
Dr
Marco Wischmeier
(IPP Garching)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Future fusion devices such as ITER and DEMO face a major challenge when limiting the thermal power load reaching the plasma-facing components, PFCs, to values below the engineering specifications. In the case of DEMO the combination of power load and erosion limitations require plasma operation at a high fraction of power dissipation, estimated to be well beyond 90%, while maintianing a...
Dr
Hiroyuki Okada
(Institute of Advanced Energy, Kyoto University)
21/10/2016, 14:00
The fast ion generation and confinement are studied by using ICRF minority heating (H minority and D majority) for the simulation study of alpha particles, whose heating is essential for fusion reactors. In a three dimensional magnetic field device, Heliotron J (R_0 = 1.2 m, a = 0.1-0.2 m, B_0 1.5 T), fast ion generation and confinement by ICRF minority heating are studied in combination...
Mr
Basilio Esposito
(ENEA)
21/10/2016, 14:00
Runaway mitigation is one of the main concerns for safe ITER operation. The disruption mitigation system, still under development for ITER, will be designed to inject the correct amount of high-Z impurities in order to dissipate thermal and magnetic energy by radiation within the mechanical limits of the structure. During the ITER disruption phase and specifically during the Current Quench...
Dr
Isabel Maria Ferreira Nunes
(IPFN/IST)
21/10/2016, 14:00
The hydrogen campaign completed at JET in 2016 has demonstrated isotope ratio control in JET-ILW using gas puffing and pellets for fuelling, Neutral Beam Injection alone or in combination, with Dalpha/Halpha spectroscopy as a diagnostic. The plasma properties such as confinement, L-H threshold, density limit depend on the isotope composition. The L-H transition power increases with the...
Dr
Katsumi Ida
(National Institute for Fusion Science)
21/10/2016, 14:00
Abrupt damping of toroidal flow associated with a transition from nested magnetic flux surface to a stochastic magnetic field is observed when the magnetic shear at the rational surface decreases to 0.5 in the Large Helical Device (LHD). 1) This flow damping and resulting profile flattening is much stronger than that expected from the Rechester-Rosenbluth model. 2) The stochastization starts...
Dr
Matthew John Hole
(Australian National University)
21/10/2016, 14:00
We highlight recent ANU-led research in energetic particle physics and multi-relaxed region MHD. Topics include (1) the inclusion of anisotropy and flow into tokamak equilibria, stability and wave-particle interaction studies, (2) the calculation of energetic geodesic acoustic modes (EGAMs) using fluid theory, (3) the development and implementation of continuum damping in 3D, (4) the...
Prof.
Michiaki Inomoto
(The University of Tokyo)
21/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
Spherical tokamak (ST) concept provides a potential for high-beta plasma confinement, however, it requires downsizing or removal of center solenoid (CS) coil because of restricted room in the central region. As one of candidates for CS-free start-up methods, combination of torus discharge by using external poloidal field coils and axial merging technique has been developed in the UTST...
Dr
Xianli Huang
(National Institute for Fusion Science)
21/10/2016, 14:00
In the Large Helical Device (LHD), the n_e profile can exhibit a peaked, flat or hollow shape. For the purpose of heavy impurity control, it is important to investigate the effect of n_e profile on the impurity transport.
Radial emissions profiles of Fe^16+ through Fe^23+ ions have been simultaneously measured in the Fe L_α array. The total iron density (N_Fe(ρ)) profile is then calculated...
Dr
Gen Motojima
(National Institute for Fusion Science)
21/10/2016, 14:00
We report the global particle balance analysis and its relationship with the plasma wall interaction emerging for the first time in long pulse helium discharges reaching 48 min on the Large Helical Device (LHD). Experimental observations show that (i) the wall retention has dynamic characteristics and the differences of the plasma facing material, which are composed of the first wall with...
Dr
Cormac Corr
(Australian National University)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Tungsten has been chosen as the material for the ITER divertor and is a contender for the wall of DEMO, which will experience temperatures in excess of 1000 K. The interaction between high-flux helium plasmas with tungsten can lead to plasma-induced surface modifications. In particular helium retention in tungsten is problematic, since helium is known to form nano-scale bubbles beneath the...
Dr
Pierluigi Bruzzone
(EPFL-CRPP)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
High Temperature Superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. The general requirements for HTS conductors and coils are presented together with a tentative roadmap for the related R&D activity. The issue of the material cost and its evolution is also discussed in comparison to the Low Temperature Superconductors (LTS) option....
Dr
Toru Tsujimura
(National Institute for Fusion Science)
21/10/2016, 14:00
The central electron temperature of high-ion-temperature plasmas was successfully increased in the large helical device (LHD) up to 7.6 keV for the central ion temperature of 6 keV and a central electron density of 1.4 x 10^(19) m^(-3) by adding a new 154-GHz gyrotron and also by optimization of the ECRH (electron cyclotron resonance heating) injection. The optimization was carried out using...
Dr
Kenji Tanaka
(National Institute for Fusion Science)
21/10/2016, 14:00
The improvement of the ion energy transport was observed in the He rich plasma of LHD. The ion thermal diffusivity around the edge pedestal region is lower than that of the gyro-Bohm prediction taking into account the effective ion mass and charge. The transport of different ion species is an important issue to predict the performance of ITER and the future reactor operation. In this paper, we...
Dr
Sarah Newton
(Chalmers University of Technology)
21/10/2016, 14:00
Neoclassical accumulation of impurities in the core of hot stellarator plasmas is a known problem.
The complexity of neoclassical transport in stellarators means that few analytic studies are available to support numerical modelling efforts, and a robust understanding of the parameter dependence of the impurity flux is still lacking.
Therefore we present an extension of the existing...
Dr
Gregory Wallace
(MIT Plasma Science and Fusion Center)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Experimental and modeling results from Alcator C-Mod and NSTX show that details of the scrape off layer (SOL) can significantly impact the effectiveness of radio frequency (RF) heating and current drive actuators. C-Mod experiments show that cold, dense conditions in the SOL lead to significant collisional absorption of lower hybrid (LH) waves outside the last closed flux surface (LCFS),...
Mr
Yuki Hayashi
(JpUNagoya)
21/10/2016, 14:00
Handling enormous plasma heat load to divertor is essential to the achievement of high fusion gain. The electron-ion recombination (EIR) process is required to reduce particle flux, leading to reduction of heat load due to the surface recombination. Further, in the ITER research plan, initial studies of H-modes are planned in helium plasmas because the predicted H-mode threshold power in...
Dr
Deliang Yu
(Southwestern Institute of Physics)
21/10/2016, 14:00
EXC - Magnetic Confinement Experiments: Confinement
Poster
Ion internal transport barriers (iITBs) are first observed in neutral beam injection (NBI) heated plasmas at the HL-2A tokamak. The position of the barrier foot, in the stationary state, coincides with the q = 1 surface within its uncertainty of measurement. iITBs can develop more easily at the beginning of NBI heating. Also, iITBs are unstable for the sawtooth plasma. Simulations reveal that...
Dr
Shinsuke OHSHIMA
(Institute of Advanced Energy, Kyoto University)
21/10/2016, 14:00
The hydrogen/deuterium (H/D) isotope effects for long range correlation (LRC) and the nonlinear relationship with turbulence were observed for the first time in a helical device, Heliotron J. The fluctuation amplitude and the correlation in toroidal direction in the low frequency range < 4 kHz are enhanced as the D2 gas becomes dominant during the shot-to-shot experiment. Turbulence scale size...
Dr
Patrick Decool
(CEA)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
In 2005, when the ITER site decision was made, the French Government decided to participate to the joint Europe-Japan implementation of the so-call “Broader Approach Activities” (BA) in support of the ITER project and DEMO activities [1,2]. The BA comprises the ITER Satellite Tokamak Programme (STP) which consists in upgrading the JT-60U machine into the largest fully superconducting and...
Prof.
Kazuya Takahata
(National Institute for Fusion Science)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
The Large Helical Device (LHD) superconducting magnet system consists of two pairs of helical coils and three pairs of poloidal coils. The helical and poloidal coils use composite conductors with pool cooling by liquid helium, and cable-in-conduit (CIC) conductors with forced cooling by supercritical helium, respectively. The poloidal coils were first energized with the helical coils on March...
Dr
Giuseppe Mazzitelli
(ENEA)
21/10/2016, 14:00
The experiments on FTU with a cooled liquid lithium limiter (CLL) (2014&2015) and subsequently with a cooled liquid tin limiter (TLL) (2016) aim at testing liquid metals (LM) under reactor relevant thermal loads of up to 10 MW/m2 in stationary conditions. In preparation of this program, improvements of the FTU facility started in 2014 with: 1) the extension of the pulse duration from 1.5 s up...
Dr
Igor Lyublinski
(RfJSCRedStar)
21/10/2016, 14:00
Application of powerful (up to 3 MW) ECR plasma heating in Т-10 tokamak with graphite limiters is pulled down with a problem of the plasma pollution at power input more than 2 MW. The use of carbon based limiters leads to formation of carbon films on a surface of a tokamak chamber wall essentially increasing of impurity flux and hydrogen recycling.
For the solution of these problems the new...
Dr
Tokihiko Tokuzawa
(National Institute for Fusion Science)
21/10/2016, 14:00
We report the discovery of the magnetic island formed in the locked-like mode in helical plasma. New analysis and observation techniques applied to the ECE signal and poloidal flow in LHD experiments show the following results. (i) The magnetic island structure is present. This indicates that the resistive interchange mode can induce the rotating magnetic island in the locking phase. (ii) The...
Dr
Maiko Yoshida
(National Institutes for Quantum and Radiological Science and Technology)
21/10/2016, 14:00
EXC - Magnetic Confinement Experiments: Confinement
Poster
Negative magnetic shear has been demonstrated to mitigate the confinement degradation typically observed with increasing the electron to ion temperature ratio (Te/Ti), and the mechanisms are now understood in terms of fluctuation measurements and gyrokinetic (GK) simulations in DIII-D steady-state plasmas. The impact of Te/Ti on plasma transport and confinement is a critical issue for ITER and...
Prof.
Nikolay Kargin
(NRNU MEPHI)
21/10/2016, 14:00
The testing experiments of the Hall sensors based on the gold nanofilms have been carried out in Joint Institute for Nuclear Research in Dubna at the JBR-2 research nuclear reactor in May 2015
The special test instrumentation has been developed to provide the investigation up to the high neutron fluences. The instrumentation permits to provide on-line measurements of the sensor parameters...
Prof.
Shuichi TAKAMURA
(Aichi Institute of Technology)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
In fusion reactor, the fusion output will be severely restricted by melting of divertor target plate made of W material. Therefore, the artificial impurities such as neon, argon, nitrogen would be injected into edge region to have a strong radiation to the whole plasma-facing surface to mitigate an overheating of a narrow divertor target surface area. Therefore, the divertor plasmas contain...
Dr
Akihiro Ishizawa
(Kyoto University)
21/10/2016, 14:00
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
As a trial in evaluating helical system designed with different concepts, we have compared two devices, the Large Helical Device (LHD) and the Heliotron J (HJ), with different magnetic field structure under two key parameters, i.e. the Mercier/interchange measure D_well and the magnetic shear s_hat, focusing on their linear drift wave instability and nonlinear evolution leading to turbulent...
Dr
Basil Duval
(Ecole Polytechnique Fédérale de Lausanne – Swiss Plasma Center (SPC), Association Euratom-Confédération Suisse(EPFL) CH-1015 Lausanne, Switzerland)
21/10/2016, 14:00
TCV’s principal goal is to explore and develop the physics basis for ITER exploitation and to aid in the development of DEMO. In the initial design, a combination of X2 and X3 ECH power was planned and installed to provide precision auxiliary heating. With a nominal <1.5T toroidal field strength, X2 heating remains limited to electron densities <~4e10^19/m3 and X3 to electron densities below...
Dr
Paul Bonoli
(Massachusetts Institute of Technology)
21/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
High field side (HFS) launch of RF power in the ion cyclotron range of frequencies (ICRF) and the lower hybrid range of frequencies (LHRF) in double null configurations in reactor grade plasmas is studied and found to represent an integrated solution that both mitigates PMI / coupling problems and at the same time opens up the possibilities of greatly improved core wave physics
Power exhaust...
Dr
Tetsutarou Oishi
(National Institute for Fusion Science)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Stochastization of edge magnetic fields has been extensively studied not only for the ELM mitigation but also for the plasma detachment and the impurity transport. Large Helical Device (LHD) has a thick stochastic magnetic field layer called “ergodic layer” located at the edge plasma with three-dimensional structure intrinsically formed by helical coils. Recently, reduction of the parallel...
Dr
Alessandro Bruschi
(Istituto di Fisica del Plasma, CNR, Milano, Italy)
21/10/2016, 14:00
The Collective Thomson Scattering (CTS) diagnostic on FTU tokamak was renewed [1] for investigations on the excitation of Parametric Decay Instabilities (PDI) by Electron Cyclotron (EC) beams in presence of magnetic islands and their effects on the EC absorption.
Experiments were performed with a gyrotron probe (140 GHz, 400 kW) launched in symmetric and asymmetric configurations with respect...
Dr
Satoshi Ohdachi
(National Institute for Fusion Science)
21/10/2016, 14:00
The central beta of the super-dense-core (SDC) plasma in the Large Helical Device (LHD) is limited by a large scale MHD event called "core density collapse" (CDC). It is found that a new type of ballooning mode, quite localized in space and destabilized from the 3D nature of Heliotron devices, is the cause of the CDC. It is the first observation that the ballooning mode is excited where the...
Dr
Daiji Kato
(National Institute for Fusion Science)
21/10/2016, 14:00
Visible emission lines of tungsten ions are useful for analysis of tungsten ion distributions at ITER because the radiation shielding of detectors is not basically necessary by using optical fibers. Here we report the result on observation of visible magnetic-dipole (M1) lines of highly-charged tungsten ions in the Large Helical Device (LHD) with tungsten pellet injection and its first...
Dr
Yoshiro NARUSHIMA
(National Institute for Fusion Science)
21/10/2016, 14:00
New observations in LHD show that the magnetic islands externally imposed by m/n = 1/1 resonant magnetic perturbation (RMP) can be maintained in an intermediate state with a finite phase shift away from the value present in vacuum. The magnetic island is maintained with a deviated phase of around 0.3pi rad from the imposed RMP. The experimental observation implies that the plasma response can...
Dr
Nicola Vianello
(Consorzio RFX, Padova, Italy)
21/10/2016, 14:00
Addressing the role of Scrape Off Layer filamentary transport is presently a subject of intense studies in fusion science. Indeed, the broadening of the Scrape Off Layer profiles in high density discharges has been observed in a number of devices. The broadening has been attributed to an increase of the convective contribution to the perpendicular transport [LaBombard, B et al. Phys. Plasmas...
Dr
Gerardo Giruzzi
(IRFM, CEA)
21/10/2016, 14:00
JT-60SA is a large fully superconducting new tokamak device being built under the Broader Approach Satellite Tokamak Programme jointly by Europe and Japan, and under the Japanese national program. The JT-60SA tokamak is due to start operation in 2019 and will be at the forefront of the international fusion programme for many years, both before and during the D-T phase of ITER operation. It...
Dr
Sebastijan Brezinsek
(Forschungszentrum Jülich GmbH)
21/10/2016, 14:00
Particle and power exhaust compatible with first wall components and the edge plasma is a key area of research and mandatory for a successful operation of ITER and beyond. Within EUROfusion, the research includes tokamak (JET and Medium-Sized Tokamaks) research studies and dedicated laboratory experiments in linear plasma devices, electron and ion beam loading facilities. The connection of...
Dr
Ryoji Hiwatari
(Japan Atomic Energy Agency)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
This paper presents the recent progress of a conceptual DEMO design in Japan. First, the divertor concept is built under the feasible engineering technology. Second, the circulating power in DEMO is precisely investigated as for the cooling power and the water detritiation system to ensure the substantial net electric power. Then, 3D eddy current analysis shows the prospect for plasma...
Dr
Peter Bagryansky
(Budker Institute of Nuclear Physics)
21/10/2016, 14:00
Active and successful studies of plasma confinement in magnetic mirror traps stopped practically in the late 80's of the last century, despite a number of potential benefits of such systems as the basis for development a nuclear fusion reactor. The reason is that the mirror concept is thought to have three unattractive characteristics. The magnets are complex, the plasma is plagued with...
Dr
Yasuo Yoshimura
(National Institute for Fusion Science)
21/10/2016, 14:00
Plasmas with the improved electron confinement state, electron internal transport barrier (e-ITB), have been investigated with short pulse discharges (< 1 s). Recent upgrade of ECH system enabled the ECH power up to 0.6 MW at the pulse duration longer than a few minutes. Effective on-axis heating with the increased ECH power realized exploration of the possibility of long pulse sustainment of...
Dr
Federico Felici
(Eindhoven University of Technology)
21/10/2016, 14:00
To maintain a high-performance, long-duration tokamak plasma scenario, it is necessary to maintain desired profiles while respecting operational limits. This requires real-time estimation of the state of the profiles, monitoring of their evolution with respect to predictions and known limits, and their active control within a desired envelope. Model-based techniques are particularly suitable...
Robert Goldston
(Princeton Plasma Physics Laboratory)
21/10/2016, 14:00
We report here advances from earlier work [1] on a lithium vapor box divertor, in which a lithium vapor cloud is held in place by local evaporation and strong differential pumping, forming a target to dissipate the heat flux from the divertor. The lowest, hottest box contains lithium vapor with nl calculated to extinguish the expected heat flux. Its bottom is wetted with a layer of lithium to...
Prof.
Yousuke Nakashima
(Plasma Research Center, JpUTsukuba)
21/10/2016, 14:00
This paper describes the characteristics of detached plasma produced by using hydrogen and noble gases together with the progress of high-heat and particle flux generation experiments in the GAMMA 10/PDX end-cell. In Plasma Research Center, University of Tsukuba, divertor simulation experiments have been started at the end-cell of GAMMA 10/PDX (E-divertor) [1]. In the GAMMA 10/PDX end-cell,...
Dr
Takuma Wakatsuki
(Japan Atomic Energy Agency)
21/10/2016, 14:00
Reduction of magnetic flux consumption of a central solenoid (CS) during a plasma current ramp-up phase is investigated using an integrated modeling code suite (TOPICS). It is shown that 27% of the CS flux can be saved in DEMO reactor by 50 MW of EC heating at rho ~ 0.5. The plasma beta is kept low in this scenario. If a safety factor profile should not be a strongly reversed shear profile in...
Dr
Takashi Minami
(Institute of Advanced Energy, Kyoto University)
21/10/2016, 14:00
A role of rational surface on electron internal transport barrier (eITB) formation of the helical plasma has been investigated in Heliotron J. The experiments have been performed on the standard magnetic configuration of B_{ax} = 1.25 The plasma with eITB is produced by a centrally focused 70 GHz ECR heating ( P_{inj}~270 kW, absorption ratio is above ~90% , N//=0.0) When bootstrap plasma...
Dr
Nirmal Kumar Bisai
(Institute for Plasma Research, Bhat, Gandhinagar-382428, India)
21/10/2016, 14:00
THD - Magnetic Confinement Theory and Modelling: Plasma–material interactions; divertors, limiters, SOL
Poster
Role of neutral gas in Scrape-off Layer (SOL) of tokamak plasma is important as it modifies the plasma turbulence. This has been investigated using a simple two-dimensional (2D) model that consists of electron continuity, quasi-neutrality, electron energy and neutral gas continuity equations. Earlier the role of the neutral gas has been studied using uniform electron temperature [1]. However,...
Timothy P. Goodman
(EPFL / SPC)
21/10/2016, 14:00
High power electron cyclotron (EC) waves are used worldwide to drive current locally in the magnetically confined plasmas in toroidal devices. Narrow beams are launched obliquely from antennas well outside the plasma, entering it through the scrape-off layer (SOL) and plasma edge to stabilize neoclassical tearing modes (NTMs).
In nearly all tokamaks, stellarators and reversed-field pinches,...
Dr
Ryuya Ikezoe
(Plasma Research Center, University of Tsukuba)
21/10/2016, 14:00
High-beta plasma confinement in a mirror field is subject to the influence of the temperature-anisotropy driven mode referred as Alfvén-ion-cyclotron (AIC) wave. The spatial structure of the AIC waves and the enhanced loss of high-energy ions owing to the AIC waves are simultaneously investigated in GAMMA 10 from a standpoint of wave-particle interaction. A clear correlation between the...
Dr
xiaodi du
(National Institute for Fusion Science)
21/10/2016, 14:00
A bursting resistive interchange mode destabilized by the resonant interaction with the helically trapped energetic ions (EIs), named as the helically trapped energetic-ion-driven resistive interchange modes, or ‘EIC’, has been identified in Large Helical Device (LHD). It can induce the significant loss of the EIs in plasma peripheral region. Therefore, the control of the EICs is important. It...
Dr
Johan Anderson
(Chalmers University of Technology)
21/10/2016, 14:00
During recent years an overwhelming body of evidence shows that the overall transport of heat and particles is to a large part caused by intermittency (or bursty events) related to coherent structures. One of the main challenges in magnetic fusion research has been to predict the turbulent heat and particle transport originating from various micro-instabilities. The ion-temperature-gradient...
Dr
Yukio Nakamura
(National Institute for Fusion Science)
21/10/2016, 14:00
Impurity behavior in normal long pulse hydrogen discharges with a flat density profile is investigated in a wide operational range and steady state operational regimes providing stationary radiation loss conditions at an acceptable level are explored in LHD. As reported before, impurity transport studies in long pulse discharges provide two different physical pictures based on neoclassical...
Dr
Shinji Kobayashi
(IAE, Kyoto Univ.)
21/10/2016, 14:00
In this study, we report on the H-mode transition triggered by high-intensity gas puffing (HIGP) in NBI plasmas of Heliotron J. Heliotron J is a medium sized (R/a = 1.2/0.17m) helical-axis heliotron device with an L/M=1/4 helical coil, where L is the pole number of the helical coil and M is the pitch number. An H-mode transition has been observed in the high density NBI plasmas. In the H-mode...
Dr
Alexander Melnikov
(NRC 'Kurchatov Institute')
21/10/2016, 14:00
The new finding in study of geodesic acoustic modes (GAMs) on the T-10 tokamak since the last IAEA FEC 2014 are described. The broadband oscillations of plasma electric potential and density in Ohmic and ECRH regimes are measured by Heavy Ion Beam Probe (HIBP) in the core plasma. At the periphery, at r/a > 0.8, the dominated GAM peak with frequency ~ 14 kHz and noticeable peak of...
Mr
Maxim Nurgaliev
(National Research Centre "Kurchatov Institute")
21/10/2016, 14:00
The results of impurity (C, O, Ar, K, Fe, and W) transport investigation in OH and ECRH discharges on the T-10 tokamak are presented in this paper. The main attention is paid to a study of the impurity removal from the plasma center during ECRH.
It is shown that in the ohmic discharges neoclassical accumulation of impurities near the plasma axis occurs. This process enhances the effect of...
Dr
Benedikt Geiger
(Max-Planck Institut für Plasmaphysik)
21/10/2016, 14:00
The behavior of fast particles in high temperature plasmas must be understood in view of future fusion devices. Fast particles result as a product of the fusion process and can be generated by neutral beam injection (NBI) or ion cyclotron heating. They heat the background plasma via collisions on electrons and ions and can, in case of an anisotropic velocity space distribution, drive...
Prof.
Kazunobu Nagasaki
(Institute of Advanced Energy, Kyoto University)
21/10/2016, 14:00
Experiments of suppressing Alfvén Eigenmodes (AE) have been made by using a second harmonic X-mode electron cyclotron current drive (ECCD) in the helical-axis heliotron device, Heliotron J. The weak magnetic shear under vacuum condition is modified into a positive magnetic shear when counter-ECCD is applied. The experiments show that global Alfvén eigenmodes (GAE) of around 130 kHz and 350 kHz...
Dr
Nikolai Gorelenkov
(PPPL, Princeton University)
21/10/2016, 14:00
EXW - Magnetic Confinement Experiments: Wave–plasma interactions; current drive; heating; energetic particles
Poster
The International Tokamak Experimental Reactor (ITER) will have a large population of non-thermal, energetic ions consisting of fusion generated alphas and beam ions injected for current profile control. Potential redistribution and/or loss of those non-thermal ions is thus of concern as it will modify heating profiles, current profiles, and losses could lead to unacceptable local heating of...
Dr
Sven Wiesen
(Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany)
21/10/2016, 14:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Poster
Identification of the mechanisms for the H-mode density limit in machines with fully metallic walls, and their scaling to future devices is essential to find for these machines the optimal operational boundaries with the highest attainable density and confinement. Systematic investigations of H-mode density limit plasmas in experiments with deuterium and hydrogen external gas fuelling have...
Dr
BENOIT LABIT
(Swiss Plasma Center (SPC) EPFL SWITZERLAND)
21/10/2016, 14:00
Dedicated experiments have been performed in TCV to investigate the heat flux onto the first wall of inboard limited L-mode plasmas. An enhancement of the heat deposition, measured with an infrared (IR) camera, is observed in the vicinity of the contact point. Indeed, for all the discharges, the parallel heat flux profile exhibits a double decay length in the scrape-off layer (SOL), with a...
Prof.
Akio Sagara
(National Institute for Fusion Science)
21/10/2016, 14:00
FIP - Fusion Engineering, Integration and Power Plant Design
Poster
The Fusion Engineering Research Project (FERP) in NIFS is conducting the conceptual design activity of the LHD-type helical fusion reactor FFHR-d1A. Recently, two options of “basic” and “challenging” have been newly defined. Conservative technologies including what will be demonstrated in ITER are chosen in the basic option, while new ideas that would possibly be beneficial for making the...
Mr
B.A. Grierson
(Princeton Plasma Physics Laboratory)
21/10/2016, 14:00
EXC - Magnetic Confinement Experiments: Confinement
Poster
Experiments in DIII-D have validated advanced models of main-ion intrinsic rotation and used dimensionless parameter scans to predict a significant amount of intrinsic torque in ITER. Recent measurements of deuterium toroidal rotation using main ion spectroscopy in DIII-D have validated predictions of Reynolds stress induced toroidal flow in the plasma core and rotation induced by ion orbit...
Mr
nicolas commaux
(oak ridge national laboratory)
21/10/2016, 14:20
The shattered pellet injection (SPI) technique has demonstrated disruption thermal quench (TQ) and current quench (CQ) control that scale to meet ITER disruption mitigation requirements. This innovative technique was tested for the last few years on DIII-D and showed improved results when compared to massive gas injection (MGI) technique in comparable conditions. Major disruptions on large...
Dr
Sergey Konovalov
(National Research Centre «Kurchatov Institute», Pl. Kurchatova 1, Moscow 123182, Russia)
21/10/2016, 15:00
Substantial fraction of the plasma current can be converted into runaway electron (RE) current in ITER disruptions. During the RE plateau stage of the disruption the kinetic energy of a runaway beam is expected to be much smaller than the magnetic one. However, at the following current termination phase, the electric field induced due to the RE loss to the wall causes the generation of new and...
Dr
Gergely Papp
(Max Planck Institute for Plasma Physics)
21/10/2016, 15:20
Disruptions in tokamaks can lead to the generation of a relativistic runaway electron (RE) beam that may cause serious damage to the first wall. The uncontrolled loss of such a high energy electron beam is intolerable and therefore the issue of how to avoid or mitigate the beam generation is of prime importance for ITER. The European medium sized tokamaks ASDEX Upgrade (AUG) and TCV have...
Dr
Lei Xue
(Southwestern Institute of Physics)
21/10/2016, 15:40
The medium-sized copper-conductor tokamak HL-2M, is currently under construction and to be put into operation in the near future. The (up-down) symmetric poloidal field coil system inside the toroidal field coils of the machine has the capability of generating high vertically-elongated plasma. Thus the VDE is an unavoidable issue for HL-2M. Meanwhile, the opposite PF current in the middle of...
Dr
Alessandro Bortolon
(PPPL)
21/10/2016, 16:40
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
DIII-D studies of high-frequency ELM pacing by pellet injection were extended to ITER scenarios at low beam torque, demonstrating ELM peak heat flux mitigation with D2 pellets, and also with Li spheres, proving the concept of ELM pacing with non fuel pellets, a technique that could potentially reduce the throughput to the pumping and fuel reprocessing systems in ITER.
Injection of D2...
Dr
Guosheng Xu
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China)
21/10/2016, 17:00
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
A new control technique for the edge-localized modes (ELMs) by pace-making with low-hybrid current drive (LHCD) power modulation has been demonstrated, for the first time, in the EAST superconducting tokamak. The achievable pace-making frequency is up to 120Hz, which appears to be limited only by the pedestal recovery time. LHCD leads to the density pump-out and local flattening of the density...
Prof.
Gunsu YUN
(Pohang University of Science and Technology)
21/10/2016, 17:20
EXD - Magnetic Confinement Experiments: Plasma–material interactions; divertors; limiters; scrape-off layer (SOL)
Oral
Edge-localized modes (ELMs) in the KSTAR tokamak appear substantially different from the conventional picture of ELMs as an explosive transport event in the plasma edge triggered by exponentially growing ballooning and external kink modes on the low field side of the plasma. The 2-D images of ELMs visualized by an advanced imaging diagnostics^1 with microsecond time resolution revealed that...
Dr
NOBUYUKI AIBA
(Japan Atomic Energy Agency)
21/10/2016, 17:40
Diamagnetic MHD equations for plasmas with fast flow were derived for the first time by introducing a suitable ordering parameter to two fluid equations. The extended Frieman-Rotenberg (F-R) equation was obtained from the diamagnetic MHD equations by focusing on impacts of the ion diamagnetic drift effect on ideal MHD stability in rotating plasmas. The MINERVA-DI code was developed to solve...
Dr
Stanislas Pamela
(CCFE - UKAEA)
21/10/2016, 18:00
Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicated pedestal models like EPED, and from non-linear MHD codes like...
Dr
Hogun Jhang
(National Fusion Research Institute)
21/10/2016, 18:20
We study the role of zonal flows in edge pedestal collapse using a reduced magnetohydrodynamic (MHD) model. A dramatic
change of dynamics happens when ideal ballooning modes are stabilized. A detailed analysis shows that a zonal flow driven instability is developed due to a strong excitation of zonal
vorticity, resulting in secondary crashes.
The presence of subsidiary bursts
after a main...
Dr
Hiroyasu Tanigawa
(Japan Atomic Energy Agency)
22/10/2016, 08:30
A. International Fusion Energy Research Centre (IFERC) has implemented DEMO research and development activities for 10 years under the Broader Approach (BA) activity. Five common issues on blanket technologies were selected and corresponding R&D has been carried out. The accomplishments of R&D were; successful production of reduced activation ferritc/martensitic steel in DEMO scale production...
Mr
Jisung Kang
(Seoul National University)
22/10/2016, 09:10
A systematic, self-consistent process to find the K-DEMO operation scenario has been investigated. Recent progress on K-DEMO scenario study explored zero-dimensional operation regime and one-dimensional current density configurations with fixed safety factor profile [1]. However, previous researches do not contain confinement optimization process for stable equilibria. In this study, an...
Prof.
Akio Sagara
(National Institute for Fusion Science)
22/10/2016, 09:30
A. The Fusion Engineering Research Project (FERP) in NIFS is conducting the conceptual design activity of the LHD-type helical fusion reactor FFHR-d1A. Recently, two options of “basic” and “challenging” have been newly defined. Conservative technologies including what will be demonstrated in ITER are chosen in the basic option, while new ideas that would possibly be beneficial for making the...
Dr
Pierluigi Bruzzone
(EPFL-CRPP)
22/10/2016, 09:50
High Temperature Superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. The general requirements for HTS conductors and coils are presented together with a tentative roadmap for the related R&D activity. The issue of the material cost and its evolution is also discussed in comparison to the Low Temperature Superconductors (LTS)...
Dr
Orso Meneghini
(General Atomics)
22/10/2016, 10:45
Accurate predictions of fusion performance requires including the strong interplay that exists between core transport, pedestal structure, current profile and plasma equilibrium. An integrated modeling workflow capable of finding the steady-state self-consistent solution to this strongly coupled problem has been developed. The workflow, leverages first principles calculations and does not...
Mr
B.A. Grierson
(Princeton Plasma Physics Laboratory)
22/10/2016, 11:05
Experiments in DIII-D have validated advanced models of main-ion intrinsic rotation and used dimensionless parameter scans to predict a significant amount of intrinsic torque in ITER. Recent measurements of deuterium toroidal rotation using main ion spectroscopy in DIII-D have validated predictions of Reynolds stress induced toroidal flow in the plasma core and rotation induced by ion orbit...
Dr
Yusuke Shibama
(NATIONAL INSTITUTES FOR QUANTUM AND RADIOLOGICAL SCIENCE AND TECHNOLOGY)
22/10/2016, 11:25
A. The JT-60SA (JT-60 Super Advanced) project is a combined project of Japan’s program for national use and the Japan-EU Satellite Tokamak Program collaboration between Japan and the EU fusion community. The main objectives are to demonstrate steady-state high-beta plasma and to support ITER through the optimization of ITER operation scenario. The JT-60SA tokamak device is designed as a...
Dr
Raffi Nazikian
(Princeton Plasma Physics Laboratory)
22/10/2016, 11:45
ELM suppression with 3D magnetic perturbations (MPs) is obtained for the first time in low
collisionality ASDEX Upgrade (AUG) plasmas following shape-matching experiments on DIII-D.
These experiments demonstrate the importance of low pedestal collisionality and strong shaping to
access ELM suppression, and reveal a remarkable similarity in the alignment of the ExB rotation profiles...
Dr
Hans-Stephan Bosch
(Max-Planck-Institute for Plasma Physics)
22/10/2016, 12:05
The main objective of the Wendelstein 7-X (W7-X) stellarator is to demonstrate the integrated reactor potential of the optimized stellarator line. An important element of this mission is the achievement of high heating-power, high confinement in fully controlled steady-state operation. In March 2014, after the installation of the last current lead in the outer vessel, the cryostat was...
Dr
Yutaka Kamada
(Japan Atomic Energy Agency)
22/10/2016, 14:20
Summary
EX/C - Magnetic Confinement Experiments: Confinement
EX/S - Magnetic Confinement Experiments: Stability
PPC - Plasma Overall Performance and Control
Dr
David Hill
(Lawrence Livermore National Laboratory)
22/10/2016, 14:50
Summary
EX/D Magnetic Confinement Experiments: Plasma–material interactions – divertors, limiters, SOL
EX/W - Magnetic Confinement Experiments: Wave–plasma interactions – current drive, heating, energetic particles
ICC - Innovative Confinement Concepts
Mr
Sergey Konovalov
(NRC "Kurchatov Institute")
22/10/2016, 15:20
TH/C -Magnetic Confinement Theory and Modelling: Confinement
TH/S - Magnetic Confinement Theory and Modelling: Stability
TH/W - Magnetic Confinement Theory and Modelling: Wave–plasma interactions – current drive, heating, energetic particles
TH/D - Magnetic Confinement Theory and Modelling: Plasma–material interactions – divertors, limiters, SOL
Prof.
Jiangang Li
(Institute of Plasma Physics, Chinese Academy of Sciences)
22/10/2016, 17:00
Summary
FIP - Fusion Technology and Power Plant Design
FNS - Fusion Nuclear Physics and Technology
SEE - Safety, Environmental and Economic Aspects of Fusion
MPT - Materials Physics and Technology
