Dr
Gleb Kurskiev
(Ioffe Physical-Technical Institute of the Russian Academy of Sciences)
16/10/2014, 08:30
Poster
The electron component is the main channel for anomalous power loss, and the main indicator of transient processes in the tokamak plasma, thus electron temperature and density profiles mainly define the operational mode of the machine. All these things impose high requirements on precision, spatial and temporal resolution of the Thomson Scattering (TS) measurements. Future tokamak-reactors...
Dr
Guoyao Zheng
(China)
16/10/2014, 08:30
Poster
Standard divertor and exact snowflake, snowflake-plus and snowflake-minus divertor configurations of HL-2M are designed. The potential properties of these divertors are analyzed and presented: low poloidal field area around X-point, connection length from outside mid-plane to the primary X-point, target plate design and magnetic field shear. The results show that the snowflake configurations...
Dr
Carmine Castaldo
(ENEA)
16/10/2014, 08:30
Poster
The concept of lower hybrid current drive (LHCD) in fusion reactors has been recently supported by the experimental evidence that lower hybrid wave power can penetrate at reactor-relevant plasma density. The control of plasma-wave nonlinear interactions occurring at the plasma edge allowed to overcome the density limit observed in previous LHCD experiments. Suitable antenna designs, optimised...
Mr
Per Helander
(Germany)
16/10/2014, 08:30
Poster
We summarise a number of recent advances in gyrokinetic theory and simulations of microinstabilities and turbulence in stellarators, and compare with tokamaks.
Trapped-electron modes (TEMs) can be very different in different types of devices, because these instabilities are excited by trapped electrons in regions of unfavourable magnetic curvature. Tokamaks and stellarators are fundamentally...
Dr
Sebastijan Brezinsek
(Germany)
16/10/2014, 08:30
Poster
Since August 2011 the JET tokamak has been operated with the ITER-Like Wall (JET-ILW): beryllium in the main chamber and tungsten in the divertor. i.e. the material configuration decided for ITER. Material erosion and fuel inventory studies are priorities of the JET-ILW programme. A large number of diagnostic tools was developed and installed to elucidate the overall material migration...
Dr
Makoto Nakamura
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
Safety of tokamak DEMO cooled by pressurized water has been studied for the first time. We have quantitatively assessed consequences of two types of accidents: ex-vessel and in-vessel loss-of-coolant accidents (LOCAs) of the first wall/blanket cooling channels. As for the former case, we have analyzed ex-vessel double-ended break of the cooling channel. The analysis result suggests that the...
Mr
Mihails Halitovs
(University of Latvia)
16/10/2014, 08:30
Poster
The accumulation of tritium in fusion devices, especially divertor region, has always been a major difficulty. The 15 – 25 micrometres tungsten W coating with Mo or Rh interlayers for carbon fibre composite (CFC) material is proposed as the latest upgrade for pure CFC divertor tiles used before. Coating should decrease the sputtering of plasma facing materials, accumulation of tritium on the...
Ms
Leena Aho-Mantila
(Finland)
16/10/2014, 08:30
Poster
Recent results of validating scrape-off layer simulations with drifts are summarized, based on detailed comparisons between 2D SOLPS5.0 fluid code solutions and L-mode experiments in the full-metal devices ASDEX Upgrade and JET. The effects of drifts in various divertor power exhaust scenarios are analysed in extensively characterized discharges, in which the levels of deuterium fuelling,...
Dr
Sebastijan Brezinsek
(Forschungszentrum Jülich)
16/10/2014, 08:30
Poster
The understanding of material migration is a key issue for a successful and safe operation of ITER. JET is used as test bed to investigate the process cycle which is connected the lifetime of first wall components by erosion and the safety due to long-term retention.
Divertor configuration: The current understanding of Be migrationin the JET-ILW can be described as follows: neutral Be and...
Prof.
Didier Moreau
(CEA/DSM/IRFM)
16/10/2014, 08:30
Poster
This paper deals with combined magnetic and kinetic control for advanced tokamak (AT) operation, using the ARTAEMIS model-based approach, a method that relies on two-time-scale semi-empirical system identification and near-optimal control theory. It is applied here to the control of AT scenarios on DIII-D, in which the safety factor profile and the normalized pressure parameter, betaN, play a...
Dr
Elena de la Luna
(CIEMAT)
16/10/2014, 08:30
Poster
The ITER Q=10 baseline scenario requires good confinement (H98≈1) at sufficiently high density (≥0.85×nGW, where nGW is the Greenwald density). In JET-C (with CFC plasma facing components), raising the plasma triangularity (averaged triangularity>0.4) was the only way found to increase the plasma density near the Greenwald density while maintaining good confinement (H98>0.9). The situation in...
Mr
Aaro Einari Järvinen
(Tekes / Aalto University)
16/10/2014, 08:30
Poster
In high confinement mode plasmas with edge localized modes in JET [1], the fluid edge code EDGE2D/EIRENE predicts transition to nitrogen induced detachment at the low-field side target plate when more than 40% of the power crossing the separatrix is radiated. This is observed both in the ITER-like wall and in the previous carbon wall environments and is consistent with experimental...
Prof.
Tomohiko Asai
(Nihon University)
16/10/2014, 08:30
Poster
The mechanism and control of spontaneous toroidal spin-up of a field-reversed configuration (FRC) have been investigated on the Nihon University Compact Torus Experiment (NUCTE). The FRC has highly favorable technological features especially as a D-3He fusion reactor core, i.e., extremely high beta, linear device geometry, natural divertor and axial mobility, allowing separation of start-up...
Dr
Ryoji Hiwatari
(Central Research Institute of Electric Power Industry)
16/10/2014, 08:30
Poster
There are several plant controls for a power plant in the electric grid system. Electric power supply from a fusion power plant(FPP) has to be also matched with the grid operation. Moreover, the grid system is now being renovated to a so-called smart-grid system, and the control functionality of a power plant in the grid system must be more sophisticated in several ten years. More...
Mr
Darin Ernst
(MIT)
16/10/2014, 08:30
Poster
This work develops a quantitative understanding of the mechanisms for increased particle transport with electron heating in (quiescent) H-mode plasmas. Our DIII-D experiments demonstrate that H-mode core particle transport and density peaking can be locally controlled by modulated electron cyclotron heating (ECH). GYRO simulations show density gradient driven trapped electron modes (TEM) are...
Dr
Sara Moradi
(Ecole polytechnique)
16/10/2014, 08:30
Poster
In recent years there has been an increasing worldwide effort in the development of the so-called hybrid or improved H-mode scenarios as a hybrid between an AT and a baseline plasma. In these scenarios, by optimising the current density profile, an enhanced normalised confinement can be achieved, as compared to the ITER baseline scenario, the ELMy H-mode. During the 2008-2009 experimental...
Mr
Roberto Zanino
(dipartimento energia, politecnico di torino)
16/10/2014, 08:30
Poster
Gyrotrons are used in current and future fusion experiments to heat the plasma with microwaves in the electron cyclotron frequency range, as well as to drive with a non-inductive mechanism a non-negligible fraction of the plasma current. For example in ITER, the Electron Cyclotron Heating and Current Drive system will be made of 24 gyrotrons, operating at 170 GHz with an output power of ~ 1 MW...
Dr
Hiroyuki Tobari
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
In the ITER NBI for plasma heating and current drive, a 1 MeV, 40 A deuterium negative ion (D-) beam is designed to be accelerated for 3600 s. The beam energy and the pulse duration of the D- beam are 2-5.5 times higher and 360 times longer than those in the negative-ion-based NBIs on LHD and JT-60U, respectively. Thus, to realize higher voltage and longer pulse duration, the generation,...
Dr
Takayuki Kobayashi
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
The development of a gyrotron and launcher operated at two frequencies, 110 GHz and 138 GHz, has made a significant progress toward electron cyclotron heating (ECH) and current drive (ECCD) in JT-60SA. High-power, long-pulse gyrotrons are required for the JT-60SA ECH/ECCD system which has the total injection power of 7 MW and the pulse duration of 100 s using 9 gyrotrons. The wave frequency in...
Prof.
Tsuyoshi IMAI
(University of Tsukuba)
16/10/2014, 08:30
Poster
EC (Electron Cyclotron) scheme is quite promising tool for heating and current drive (H&CD) and plasma control for present and future devices up to Demo and Commercial reactors. Development of gyrotron is a key to open this promising door. Multi-MW and multi-frequency technologies are major issues to challenge for robust and cost effective reactor heating system. In University of Tsukuba,...
Dr
Roland Sabot
(CEA, IRFM)
16/10/2014, 08:30
Poster
Core turbulence in tokamak plasmas is driven by two main instabilities: Ion Temperature Gradient (ITG) and Trapped Electron Modes (TEM). Experimental identification is challenging because both instabilities are unstable in the limit of long wavelengths. Analysis of Tore Supra and Textor discharges suggest a link between the onset of quasi coherent modes, a broad secondary peak on the...
Mr
Shigeru Inagaki
(Japan)
16/10/2014, 08:30
Poster
Here we developed research methods of plasma turbulence transport associated with the non-local features. The ECH modulation experiment and the higher harmonic analysis of the heat wave indicated: (i) propagation of the change of Te at the time of switch-off/on of ECH power is about 5 times faster than that of perturbation itself, (ii) propagation of the higher (7th) harmonic of the Te...
Mr
Jerry Hughes
(USA)
16/10/2014, 08:30
Poster
Improvement in global confinement and fusion performance are found to be correlated with the pressure at the top of the edge barrier ("pedestal height") both in experiments and theory. Performance predictions for future devices such as ITER rely on experimental validations of the hypothesis in the predictive models. To date, the leading model for pedestal structure prediction is EPED. This...
Dr
Gary L. Jackson
(General Atomics)
16/10/2014, 08:30
EXS - Magnetic Confinement Experiments: Stability
Poster
With lithium injection, an enhanced pedestal with ELM-free periods up to 350 ms has been observed, accompanied in the edge region by increased density fluctuations and reduced intrinsic impurity accumulation in the core plasma. The increase in pedestal width is rapid, usually occurring in a few ms and can expand by more than 100% during the ELM-free phases with lithium injection. This is...
Dr
Guangzhou Hao
(Southwestern institute of physics)
16/10/2014, 08:30
Poster
The toroidal plasma flow, and/or flow shear, plays a critical role in affecting the macroscopic magnetohydrodynamic (MHD) instabilities (e.g. the resistive wall mode, the tearing mode, etc.) as well as the plasma confinement. A finite toroidal plasma rotation generated without external momentum input is very important for ITER, since its momentum input is expected to be small in relation to...
Mr
Paolo Ricci
(Switzerland)
16/10/2014, 08:30
Poster
The steady-state heat load onto the plasma facing components of tokamak devices depends on the SOL width, which results from a balance between plasma outflowing from the core region, turbulent transport, and losses to the divertor or limiter. Understanding even the simplest SOL configurations, like circular limited plasmas, is a stepping-stone towards more complicated configurations, with...
Dr
WON JAE CHOI
(NFRI(Nationl Fuson Research Institute))
16/10/2014, 08:30
Poster
The importance of fundamental research for society and economic life has been underscored since the 1990’s. In addition to scientific advancements, many ‘big science’ institutes such as CERN also generate various types of economic and innovation benefits for their countries’ economies. The direct and corollary financial effects generated by procurement activity have been investigated in...
Mr
Arkadi Kreter
(Germany)
16/10/2014, 08:30
Poster
The fuel retention and the lifetime of plasma-facing components are critical factors potentially limiting the availability of a magnetic fusion reactor. It is necessary to test how plasma-facing materials perform with respect to hydrogen retention and erosion under the realistic mixed species plasma conditions including impurities like helium and argon. This contribution summarizes the...
Dr
Kenji Imadera
(Graduate School of Energy Science, Kyoto University)
16/10/2014, 08:30
Poster
By means of a newly developed 5D toroidal global gyrokinetic code with heat source/sink, we investigated the nonlocal characteristics of flux-driven ITG turbulence to clarify the underlying mechanism of avalanches, profile resilience and their dynamic responses in toroidal system.
We found that the turbulent transport and associated profile relaxation are dominated by two processes. One is...
Dr
Timo Kiviniemi
(Aalto University)
16/10/2014, 08:30
Poster
The global full f nonlinear gyrokinetic code ELMFIRE is used for simulating geodesic acoustic modes (GAMs) over a wide range of parameters. For radial wavelength of GAMs, the agreement between analytic value and simulation results is shown to be good for low collisional regime which is not the case with high collisionality. The isotope scan considering hydrogen, deuterium, tritium and helium...
Dr
David Hatch
(Institute for Fusion Studies, University of Texas at Austin)
16/10/2014, 08:30
THC - Magnetic Confinement Theory and Modelling: Confinement
Poster
The gyrokinetic Gene code is used to study Inter-ELM H-mode pedestal profile evolu- tion for an ASDEX-Upgrade discharge. Four main instabilities are observed during various inter-ELM phases—density gradient driven drift waves (DW), microtearing modes (MTM), kinetic ballooning modes (KBM), and electron temperature gradient (ETG) modes. DWs are the dominant pedestal instability during the early...
Mr
Scott Parker
(USA)
16/10/2014, 08:30
Poster
For a better understanding of the complicated physics of the inter-related "intermittent plasma objects (blobs)" and divertor heat-load footprint, the full-function gyrokinetic PIC code XGC1 has been used in realistic diverted geometry. Neoclassical and turbulence physics are simulated together self-consistently in the presence of Monte Carlo neutral particles. Blobs are modeled here as...
Prof.
Victor Vdovin
(NRC Kurchatov Institute)
16/10/2014, 08:30
Poster
The innovative efficient current drive scheme in the tokamaks using the Helicons radiation has recently been proposed [1] to stabilize high normalised beta strongly shaped reactor relevant plasmas. The scheme has shown broad current profile tailoring capabilities in modern tokamaks, reactors FNSF-AT, ITER and DEMO, and uses reliable RF CW technique developed for large accelerators. This...
Mr
Stephen Wukitch
(MIT PSFC)
16/10/2014, 08:30
Poster
Future fusion reactors will present more severe constraints on ion cyclotron range of frequency (ICRF) heating and current drive actuators than ITER. Reliably coupling power to the plasma despite load variations is critical. In addition, ICRF interaction with the edge plasma, particularly impurity contamination and enhanced localized heat loads, is challenging. We report on progress...
Dr
Jozef ONGENA
(Plasma Physics Lab, ERM-KMS, Brussels)
16/10/2014, 08:30
Poster
Discharge wall conditioning is an effective tool to improve plasma performance by (i) reducing the generation of plasma impurities liberated from the wall and (ii) controlling the recycling of hydrogenic fluxes. On ITER discharge wall conditioning will be employed as well for (iii) mitigating the tritium inventory build-up, for which one relies mostly on the removal of tritium-rich...
389.
ICRF Heating Experiment Using the Faraday Shield Less Antenna and New High Power Antenna in LHD
Mr
Tetsuo Seki
(Japan)
16/10/2014, 08:30
Poster
In ICRF heating experiments, impurity influx has been a serious problem from the early phase of fusion research. It was thought that the RF electric field parallel to the magnetic field line near the antenna caused the impurity influx, and Faraday Shield (FS) was thought to be necessary to shield out such an electric field. If the FS is possible to be removed, the design and the construction...
Prof.
Victor Vdovin
(NRC Kurchatov Institute)
16/10/2014, 08:30
Poster
This system of ICRH/CD should provide RF heating and current drive in plasma of tokamak T- 15. A total of 6 MW RF power in the plasma should be initially available from the IC system. ICRH and CD system consists of three in-port antennas, corresponding transmission lines, delivering RF energy from sources, matching system , and ancillary subsystems.
Functional requirements in physics •...
Dr
Ernesto Augusto Lerche
(LPP-ERM/KMS)
16/10/2014, 08:30
Poster
Since 2011 JET has been operating with a full-metal ITER-like wall (ILW), with most of the main chamber plasma facing components made from beryllium (Be) and featuring a bulk tungsten (W) divertor [1,2]. In H-modes with PNBI>15MW of neutral beam injection (NBI), accumulation of heavy impurities (in particular W) has become a concern, since aside from degrading the plasma performance it can -...
Mr
Emmanuel Joffrin
(France)
16/10/2014, 08:30
Poster
The transition from a full carbon wall to tungsten components in the divertor and beryllium components plasma facing components in JET has been an essential step in 2011 for demonstrating the compatibility of ITER scenario with a metallic environment. Specific exploration of the divertor geometry have been conducted in JET in 2013 to identify the divertor conditions showing the optimum...
Dr
Eugene Mukhin
(Ioffe Physical Technical Institute)
16/10/2014, 08:30
Poster
The routine operation of ITER leads to retention of a sufficient fraction of the tritium fuel. This requires an inventory of radioactive material which must be limited and monitored. As a nuclear device, ITER must limit in-vessel tritium retention to minimize the consequences of potential accidents during normal operation and maintenance as well as to reduce the potential for environmental...
Dr
Sergei Gerasimov
(CCFE, UK)
16/10/2014, 08:30
Poster
Asymmetrical disruptions may occur during ITER operations. It is possible that they may be accompanied by large sideways forces and by toroidal rotation. This is of particular concern because resonance with the natural frequencies of the vacuum vessel and in-vessel components could lead to the high dynamic amplification of the forces.
Roughly half of all JET disruptions have toroidally...
Dr
Gary M. Staebler
(General Atomics)
16/10/2014, 08:30
Poster
The two dimensional momentum transport of the mean field (i.e. low frequency compared to the turbulence) ExB toroidal and ion poloidal velocities are modeled with both collisional and turbulent contributions to the transport equations. The radial and temporal evolution of the edge barrier is modeled. It will be shown that there are both normal one-step L/H transitions to suppressed turbulence...
Dr
Ekaterina Sorokina
(NRC "Kurchatov Institute")
16/10/2014, 08:30
Poster
Magnetic and current structures arising due to resonant perturbations of an equilibrium current-carrying magnetic configuration are analyzed using the Hamiltonian formalism. Special attention is paid to axisymmetric tokamak and pinch configurations. It is shown that, due to the very different dependencies of the magnetic and current rotational transforms on the plasma pressure, the resonances...
Dr
Philippe Jacquet
(CCFE)
16/10/2014, 08:30
Poster
Experiments have been performed under the coordination of the ITPA on several tokamaks, including ASDEX Upgrade (AUG), JET & DIII-D, to characterise the increased ICRF antenna loading achieved by optimising the position of gas injection relative to the RF antennas. On DIII-D, AUG and JET (with the C-wall and recently the ITER-Like Wall) a 50% increase in the antenna loading was observed when...
Mr
Guy Matthews
(Culham Centre for Fusion Energy)
16/10/2014, 08:30
Poster
Our priority for the 2013 JET campaigns was to provide relevant data for the ITER decision on whether to initially install a full tungsten divertor rather than a design with carbon at the strike points. A key element of this was an experiment using a specially modified divertor module which was used to study the characteristics and impact of ELM induced melting of bulk tungsten on JET...
Mr
Shinya Maeyama
(Japan)
16/10/2014, 08:30
Poster
Understanding electron heat transport is one of the critical issues in ITER. Although electron temperature gradient (ETG) driven turbulence has been regarded as a candidate of electron heat transport, recent multi-scale plasma turbulence simulations have reported that ion-scale instabilities such as ion temperature gradient modes (ITGs) and trapped electron modes (TEMs) dominate heat transport...
Mr
Marc Goniche
(France)
16/10/2014, 08:30
Poster
Interaction of radio-frequency waves with the edge plasma of tokamaks from which the wave is launched is now well recognized for waves in the Ion Cyclotron Range of Frequency (ICRF) but also in the range of Lower Hybrid Current Drive (LHCD) frequencies.
A dynamic Stark spectroscopic measurement was carried out near a Tore Supra LHCD antenna, demonstrating that indeed the electric field...
Dr
Sergey Medvedev
(Keldysh Institute of Applied Mathematics, RAS, Moscow, National Research Nuclear University MEPhI, Moscow, Russia)
16/10/2014, 08:30
ICC - Innovative Confinement Concepts
Poster
Fusion research has to solve the power handling toward fusion demonstration power reactor (DEMO). A tokamak plasma with strongly negative triangularity may offer such an opportunity as an innovative concept. The present paper discusses the edge stability, beta limits and power handling issues for the negative triangularity tokamaks. The edge MHD stability is the most crucial item for power...
Prof.
Yuichi Takase
(University of Tokyo)
16/10/2014, 08:30
Poster
Although the spherical tokamak (ST) has the attractiveness of good stability at high beta, it is presently considered impractical to realize a compact ST fusion reactor unless the central solenoid can be eliminated. Non-inductive plasma current start-up and sustainment by waves in the lower-hybrid (LH) frequency range (200 MHz) have been studied on the TST-2 spherical tokamak (major radius R_0...
Dr
Naohiro Kasuya
(Kyushu University)
16/10/2014, 08:30
Poster
Hysteresis in the flux-gradient relation (similar to what has been revealed by the dynamical response to the heating modulation [S. Inagaki, et al., Nucl. Fusion 53 (2013) 113006.]) is found in the global nonlinear turbulence simulation for the first time. Here we report (i) the abrupt increase of the heat flux after the gradual change of the flux and pressure gradient on the onset of the...
Dr
GUIDO CIRAOLO
(CEA, IRFM)
16/10/2014, 08:30
Poster
Operating a fusion reactor requires handling high heat loads on the divertor plasma facing components. In support of the ITER divertor strategy, the WEST project on Tore Supra aims at studying tungsten monoblocks behaviour when submitted to heat flux, and high plasma fluence, representative of ITER conditions during long pulses. A considerable simulation effort is dedicated to properly...
Dr
Ephrem Delabie
(EURATOM-FOM association DIFFER , The Netherlands)
16/10/2014, 08:30
Poster
The expected threshold power (Pth) required to access H-mode operation on ITER is extrapolated from a multi-machine scaling that is strongly weighted to a dataset of JET carbon wall discharges. To assess differences in Pth due to the change to a Be/W-wall, a series of experiments has been conducted at JET to measure Pth as function of plasma density for different Bt/Ip [1]. At medium to high...
Dr
Eleonora Viezzer
(Germany)
16/10/2014, 08:30
Poster
Extensive studies have shown that the pedestal Er profile in H-mode and asymmetric density and flow profiles of impurity ions are consistent with neoclassical predictions. While the ions set the background flow profile and their transport properties can be described by neoclassical modelling, the mechanisms which determine the electron density and temperature profiles are more varied.
A...
Dr
Vladislav V Plyusnin
(Instituto de Plasmas e Fusão Nuclear, Associação EURATOM-IST, Instituto Superior Tecnico)
16/10/2014, 08:30
Poster
The database on runaway electrons (RE) collected in JET with plasma facing components based on carbon-fibre composite tiles (JET-C) has been updated by recent results of experiments on disruptions and RE generation in JET with full-metal ITER-like wall (JET-ILW). Unlike the first operations of JET-ILW, which didn’t reveal the probability of runaway electron generation, new experiments with...
Ms
Costanza Maggi
(Germany)
16/10/2014, 08:30
Poster
The pedestal confinement of JET-ILW H-modes is presented and their stability investigated in the framework of P-B stability and the predictive code EPED. The changes in wall composition from C to Be/W point to the possible role of neutral recycling, low-Z impurities and scrape-off-layer physics in pedestal stability, highlighting the need for refinement of models predicting the pedestal...
Mr
Dehong Chen
(Institute of Nuclear Energy Safety Technology (INEST),Chinese Academy of Sciences)
16/10/2014, 08:30
Poster
A fusion power plant based on long-pulsed operated tokamak fusion reactor was proposed to avoid the issues of steady-state operation of non-inductive current driven methods. The plasma current, excepting the bootstrap current, is only driven inductively to sustain several hours. The burning stage can be sustained by α heating and started by ohmic and radio frequency wave heating methods. Thus,...
Mr
Vladimir Svidzinski
(USA)
16/10/2014, 08:30
Poster
A novel plasma confinement concept in which plasma is confined in a dynamic steady state by a pressure of rotating magnetic field in a toroidal geometry will be presented. The confining rotating magnetic field is created by AC currents driven by applying oscillating voltages to toroidal and poloidal gaps (insulated horizontal and vertical cuts) in the shell of the torus with 90 degrees phase...
Prof.
Chijin Xiao
(Canada)
16/10/2014, 08:30
Poster
Plasma current start-up in the iron core STOR-M tokamak (R=0.46 m, a=0.12 m and Bt=0.6 T) without the central solenoid (CS-less) has been demonstrated. The plasma current can be maintained during the iron core saturation phase. In particular, effects of the turn number of the outer OH coils (N=4 or N=6) on the CS-less discharges have been compared. The plasma current start-up is reproducible...
Dr
Thierry Loarer
(CEA, IRFM, France)
16/10/2014, 08:30
Poster
In ITER, isotopic exchange by deuterium could be envisaged as a method for minimising the tritium inventory in the vessel. In JET ITER-Like Wall (JET-ILW) an isotopic plasma wall changeover experiment has been carried out to determine the amount of particle accessible by changing the plasma from H to D. The results of this series are presented and discussed in this paper.
Starting with a wall...
Prof.
Yasushi Ono
(University of Tokyo)
16/10/2014, 08:30
ICC - Innovative Confinement Concepts
Poster
We have been developing a new type of divertor concept: “dynamic divertor” composed of periodic ejection of plasmoid from a core-plasma and its gas-puff cooling, to reduce significantly heat flux to divertor plates. Our TS-4 experiment and PIC simulation consistently solved the plasmoid formation and pinch-off mechanisms essential to the dynamic divertor operation. We found the acceleration...
Dr
Emmanuelle Tsitrone
(CEA)
16/10/2014, 08:30
Poster
Power exhaust is one of the main challenges for next step fusion devices. The WEST project (Tungsten (W) Environment in Steady State Tokamak) is targeted at paving the way for the ITER divertor procurement and operation. It consists of implementing a divertor configuration and installing an ITER like actively cooled tungsten divertor in Tore Supra, taking full benefit of its unique long pulse...
Dr
Atsushi Kojima
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
The long pulse generation of the powerful negative ion beams of 500 keV, 22 A (130 A/m^2) and 1MeV, 40 A (200 A/m^2) is the essential challenge to realize the negative-ion-based neutral beam injectors (NBIs) for JT-60SA and ITER, where 10 MW D0 beam for 100 s and a 16.5 MW for 3600 s are designed, respectively. In Japan Atomic Energy Agency (JAEA), after the achievements of the beam current...
Mr
Vanni Toigo
(Italy)
16/10/2014, 08:30
Poster
In ITER, additional heating systems are provided to reach higher plasma temperature and to sustain fusion conditions; among them two Neutral Beam Injectors (NBI) will be installed, capable of producing high energy beams up to 1MeV, to transfer to the plasma up to 16.7MW and to operate up to 1 hour.
Such a high NBI performance has never been reached. A research and development plan has been...
Dr
ShiChong Guo
(Consorzio RFX)
16/10/2014, 08:30
Poster
Recent results of the theoretic studies on Resistive Wall Modes (RWM) in Reversed Field Pinch (RFP) plasmas are reported. Different features of RWM instabilities between RFP and tokamak are investigated in order to provide in-depth understanding on RWM physics. The toroidal MHD-kinetic hybrid stability code MARS-K [1] was applied to the studies, taking into account the full kinetic effects of...
Mr
Antonio Masiello
(European Commission)
16/10/2014, 08:30
Poster
The development of the Neutral beam system for ITER has been progressing well thanks to the start of the operations of the ELISE (Extraction from a Large Ion Source Experiment) at the Max Planck Institute for Plasma Physics in Garching, Germany, and to the big effort devoted to the establishment of the ITER Neutral Beam (NB) Test Facility in Padua, Italy.
This paper presents the main...
Dr
Yasuhisa Oda
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
To study the operational performance of ITER EC heating and current drive system (H&CD), a mock-up of the ITER mm wave system has been assembled using the high power long gyrotron test stand in JAEA. The prototype system is composed of the primary parts of the EC H&CD system, including: 170GHz gyrotron, power supply, transmission line (TL) and mock-up of equatorial launcher (EL) and control...
Mr
WILLIAM OSEI-MENSAH
(GHANA ATOMIC ENERGY COMMISSION)
16/10/2014, 08:30
Poster
Assessing the amount, type and energy of radiation encountered requires knowledge of radiation source and the shielding effect of the type of material between the radiation source and the area of interest. The choice of elements in structural materials such as stainless-steel can reduce the radiation levels due to particle activation. The dose rate to workers and electrical components are...
Mr
Morten Lennholm
(European Commission)
16/10/2014, 08:30
Poster
ELMs and Sawteeth, located in different parts of the plasma, are similar from a control engineering point of view. Both manifest themselves through quiescent periods interrupted by periodic collapses. For both, large collapses, following long quiescent periods, have detrimental effects while short periods are associated with decreased confinement. It is of interest to implement control systems...
Mr
Joachim Herb
(Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH)
16/10/2014, 08:30
Poster
During the last decades a safety concept for fusion power plants (FPP) has been developed which is based on the defence-in-depth safety concept of installations with radioactive inventories, especially nuclear fission power plants.
We present the main findings of a thorough literature study to reveal the current state of the fusion safety concept. The safety concept for FPPs like the concept...
Dr
Akinobu Matsuyama
(Japan Atomic Energy Agency)
16/10/2014, 08:30
Poster
To extend the capability of RE mitigation is an urgent issue towards the safety operation of ITER. We investigate the RE losses induced by low-order MHD instabilities and clarify a dominant mechanism for determining the energy dependence of the onset of RE orbit stochasticity. This is due to that for highly relativistic REs, sideband resonance of the orbit shift with macroscopic modes is much...
Prof.
Mathias Groth
(Aalto University)
16/10/2014, 08:30
Poster
Further steps have been taken in validating predictions of detached divertor simulations with the edge fluid code EDGE2D coupled to the neutral Monte-Carlo code EIRENE for JET low confinement mode plasmas in the ITER-like wall configuration. Fully detached and strongly recombining divertor plasmas close to the density limit were characterized experimentally by bolometry, spectroscopy, and...
Mr
Philip B. Snyder
(USA)
16/10/2014, 08:30
Poster
A new “Super H-mode” regime is predicted at very high pedestal pressure, enabling pedestal height and predicted fusion performance substantially higher than for H-mode operation. This new regime exists due to a bifurcation of the pedestal solution that occurs in strongly shaped plasmas above a critical density. The Super H-mode regime is predicted to be accessible, and to increase fusion...
Dr
Alexander B. Kukushkin
(NRC Kurchatov Institute, Russia)
16/10/2014, 08:30
Poster
Theoretical model suggested for ITER H-alpha High-Resolution Spectroscopy (HRS) is validated against recent JET ITER-like wall (ILW) experiments. The model assumes reconstruction of neutral hydrogen isotopes density in the SOL, and evaluation of the recycling flux from the main chamber first wall, via solving a multi-parametric inverse problem with allowance for (i) strong divertor stray light...
Prof.
Dmitry Morozov
(NRC "Kurchatov Institute")
16/10/2014, 08:30
Poster
The problem of thermal equilibrium and density limit in contemporary tokamaks has been discussed by many authors. As it is well known a part of disruptions is related to the radiation collapse [1,2]. However, the influence of the fusion energy production has not yet been investigated. The problem for a tokamak-reactor is analyzed in the present paper. The empirical Greenwald criterion n_c~I...
Prof.
Victor Ilgisonis
(NRC "Kurchatov Institute")
16/10/2014, 08:30
Poster
A possibility to organize in the center of a tokamak the large ergodic area surrounded by nested magnetic surfaces is discussed. The ergodicity of the area dense fulfilled by the magnetic field lines provides the constancy of plasma pressure that mostly removes some drift and current instability in the area. The surrounding magnetic surfaces commonly response for the plasma thermal insulation....
Dr
Carine Giroud
(CCFE)
16/10/2014, 08:30
Poster
The reference scenario for achieving Q=10 in ITER is an integrated type-I ELMy H-mode scenario that combines good core plasma performance of H_98_(y,2)~1,beta_N ~1.8, <n>/nGW ~0.85, and high fuel purity (Z_eff~1.6), together with edge parameters compatible with the Be/W Plasma Facing Components (PFCs) in stationary conditions for t_stat~400s (i.e. 100 times the energy confinement time tauE)....
Dr
Muyi Ni
(Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences)
16/10/2014, 08:30
Poster
The environment assessment of large inventory tritium in fusion reactor is an important issue before fusion energy can be considered for commercial use. In this paper, a new approach for assessing the radioactive consequences of tritium release under accident events has been developed.
Firstly, the tritium fuel cycle in fusion reactor was simulated based on system dynamics method, and the...
Mr
George R. McKee
(USA)
16/10/2014, 08:30
Poster
Multi-scale turbulence properties are significantly altered and typically exhibit increased amplitude in high-beta inductive plasmas as parameters approach those anticipated in burning plasmas. These increases, observed with multiple fluctuation diagnostics in high performance H-mode plasmas on DIII-D, explain the consequent local transport and global energy time confinement response. Burning...
Dr
Hideaki Miura
(National Institute for Fusion Science)
16/10/2014, 08:30
Poster
Two-fluid effects on pressure-driven unstable modes are studied numerically to understand physics in linear and nonlinear evolution of them in a heliotron device. Full 3D simulations show that the introduction of the two-fluid term can bring about the deterioration of the stabilizing effect of the parallel heat conduction through generation of large magnetic perturbations, to lead to a...
Mr
Vladimir Rozhansky
(Russian Federation)
16/10/2014, 08:30
Poster
Modeling of the impurities distribution in the pedestal region of ASDEX-Upgrade H-mode shot was done using the B2SOLPS5.2 transport code. Strong LFS-HFS asymmetry of B+5 density and strong decoupling between parallel velocity distribution of the impurities and the main ions was obtained in qualitative agreement with the experimental observations [1]. Similar asymmetry was obtained earlier in...
Dr
Klaus Schmid
(Max-Planck-Institut für Plasmaphysik)
16/10/2014, 08:30
Poster
The migration of first wall material due to erosion, plasma transport and re-deposition is one of the key challenges in current and future fusion devices. To predict erosion/re-deposition patterns and to understand the underlying principal processes, the global simulation code WallDYN was developed that couples the evolution of the first wall surface composition to plasma impurity transport....
