Dr
Yoshitaka Mori
(The Graduate School for the Creation of New Photonics Industries)
10/16/14, 2:00 PM
Poster
For inertial confinement fusion, the high-density compression and core heating are essential processes. National Ignition Facility (NIF) is a promising candidate for the development of a fusion power plant. However, a self-ignition scheme, that is, to burn the core in implosion itself is not straightforward as expected. A potential solution for this is the fast-ignition scheme, because this...
Dr
Ryohei Hanayama
(The Graduate School for the Creation of New Photonics Industries)
10/16/14, 2:00 PM
Poster
We succeeded in injection of spherical deuterated polystyrene bead pellets at 1 Hz and symmetrical engagement and irradiation of them with two ultra-intense laser beams. (i) This is the first demonstration of ultra-intense laser engagement of injected flying pellets. The laser intensity was high enough to produce a DD neutron yield of 9.5×10^4/4pi sr/shot. (ii) We observed channel formation...
Mr
Hong Jin Kong
(Korea, Republic of)
10/16/14, 2:00 PM
Poster
The authors propose the high-energy and high repetitive fs/ps laser system which uses the output beam of a coherent beam combination laser using stimulated Brillouin scattering phase conjugate mirrors (SBS-PCMs) as the pump beam of optical parametric chirped-pulse amplification (OPCPA). To verify the feasibility of the OPCPA system, the authors will utilize 4 kW(4 x 0.1 J @10 kHz/10 ns)...
Dr
Mikirou Yoshinuma
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
An extremely hollow carbon impurity profile (impurity-hole) has been observed associated with increase of ion temperature gradient in the discharges with ion-ITB on LHD. Simultaneous achievement of the impurity-hole and ion-ITB is favorable feature in nuclear fusion plasma, where both good energy confinement and ash exhaust are required.
The impurity-hole is characterized as small diffusion...
Mr
Alexander Tukachinsky
(Ioffe Institute)
10/16/14, 2:00 PM
Poster
The bursts of high frequency (~ 1 МHz) oscillations have been registered by magnetic probes in experiments carried out on the TUMAN-3M tokamak. The line averaged plasma density was ne < 2.5*1019 m-3 and BT ~ (0.7 – 1)T, the regimes were both ohmic and NBI-heated.
The gaps in oscillation spectra between high and low frequency parts of the spectra were observed under conditions mentioned...
Dr
thawatchai Onjun
(Sirindhorn International Institute of Technology)
10/16/14, 2:00 PM
Poster
The formation of transport barriers, including both ETB (edge transport barrier) and ITB (internal transport barrier), in tokamak plasma is investigated using bifurcation concept. A set of heat and particle transport equations with both neoclassical and anomalous effects is used to represent the plasma in slab geometry. The neoclassical coefficients are assumed to be constant, while the...
Dr
Kwan Chul Lee
(National Fusion Research Institute)
10/16/14, 2:00 PM
Poster
An analysis of radial electric field formation in the core region of tokamak is developed based on the gyro-center shift (GCS) theory and its calculation is compared with experimental measurements on KSTAR and NSTX. The GCS theory suggests the radial electric field formation by the perpendicular component of neutral beam injection (NBI) momentum input [1]. Most of induced ExB drift is balanced...
Prof.
Satoru Sakakibara
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Effects of low-n MHD instabilities on plasma performance have been assessed in the regime where an achieved beta value is regulated by instabilities. In stellarators and heliotrons, interchange instability driven by pressure gradient is most concerned to impose the limit of the achievable beta value. Previous experiments in LHD show that high beta plasma with more than 5 % was successfully...
Dr
MASAYUKI YOKOYAMA
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
The integrated transport analysis suite, TASK3D-a, has enhanced energy transport analyses in LHD. It has elucidated the systematic dependence of ion and electron energy confinement on a wide variation of plasma parameters, and the fitting expressions for ion and electron heat diffusivities with local plasma parameters.
Conventionally, scaling laws for the global energy confinement time...
Mr
Hideo Nagatomo
(Osaka University)
10/16/14, 2:00 PM
Poster
A compression of external magnetic field by a laser driven implosion is studied using two dimensional radiation hydrodynamic simulation. The simulation results show that (i) it is possible to compress the magnetic field to be 10kT (108 Gauss), and (ii) the strong magnetic field should affect the implosion dynamics because of the suppression of the electron heat flux which across strong...
Ms
Elena Koresheva
(Russian Federation)
10/16/14, 2:00 PM
Poster
A central feature of an inertial fusion energy (IFE) power plant is a target that must be delivered to the target chamber center at a rate of about 1–15 Hz.
A high rep-rate target supply system, which operates with moving free-standing targets (FST) is the culmination of a 25-year science-&-technology effort of the Lebedev Physical Institute (LPI) in collaboration with other Russian...
Mr
Takashi Sekine
(Hamamatsu Photonics K.K.)
10/16/14, 2:00 PM
Poster
Development of a kilo-Joule class diode-pumped solid-state laser (kJ-DPSSL) as a beam line of Mega–Joule class driver is necessary for realization of inertial fusion energy. We conceptually designed a kJ-DPSSL for an inertial fusion mini-reactor CANDY. The CANDY is the kJ-DPSSL driven integrated fusion mini-reactor based on fast ignition scheme. The driver consists of two implosion laser...
41.
Control of Electron Beam Using Strong Magnetic Field for Efficient Core Heating in Fast Ignition
Dr
TOMOYUKI JOHZAKI
(Graduate School of Engineering, Hiroshima University)
10/16/14, 2:00 PM
Poster
One of the most crucial issues of fast ignition is efficient core heating by laser produced fast electron beam. The main factors in preventing efficient heating are (1) too high fast electron energy and (2) too large beam divergence. The fast electron energy could be controlled by eliminating pre-plasma generation and by using heating laser with shorter wavelength. With respect to the beam...
Mr
Yasuhiko NISHIMURA
(The Graduate School for the Creation of New Photonics Industries, Toyota Technical Development Corpration)
10/16/14, 2:00 PM
Poster
Laser fusion experiment extracts net energy from fuel on the National Ignition Facility (NIF) by using 1.8 MJ, 500 TW single shot laser. Following an effort of this scientific proof of ignition, engineering development needs to start on Inertial Fusion Energy (IFE) by using a repetitive fusion driver. To realize the IFE power plant, one key issue is a high-repetition-rate laser of kJ-class or...
Dr
Linda E Sugiyama
(USA)
10/16/14, 2:00 PM
Poster
Understanding the stability and behavior of 3D helical modes in the core of an axisymmetric toroidal configuration remains one of the challenges of fusion research [1-3]. A new type of periodic fishbone-like instability with a (1,1) internal kink-like structure [3] has been observed in Alcator C-Mod tokamak during the development of advanced non-inductive scenarios using radio frequency lower...
Dr
Kiyofumi Mukai
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Reduction of heat and particle loads to the divertor is crucial to the realization of a fusion reactor. Divertor detachment is a favorable mode of operation for this purpose. In this study, impurity seeding was conducted in the Large Helical Device (LHD) using neon (Ne) puffing. Enhanced radiation loss and reduction of the divertor heat load were observed without significant changes in stored...
Prof.
Izumi Murakami
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Quantitative tungsten study with reliable atomic modeling is important for successful achievement of ITER and fusion reactors. We have developed tungsten atomic modeling for understanding the tungsten behavior in fusion plasmas. The modeling is applied to the analysis of tungsten spectra observed from currentless plasmas of the Large Helical Device (LHD) with tungsten pellet injection. We...
Mr
Hyun-Seok Kim
(Seoul National University)
10/16/14, 2:00 PM
Poster
Control of plasma profiles and magneto hydrodynamic (MHD) instabilities is essential to establish advanced operation scenarios, a promising approach towards DEMO. For the purpose of simultaneous control of these plasma profiles and MHD instabilities, an integrated real time control algorithm is developed in this work. The developed control algorithm deals with electron temperature (Te) and...
Dr
Atsushi Sunahara
(Institute for Laser Technology)
10/16/14, 2:00 PM
IFE - Inertial Fusion Experiments and Theory
Poster
In the conventional fast ignition scheme of inertial confinement fusion (ICF), the heating laser energy is transferred to energetic fast electrons towards the imploded plasma core and heats it while the high dense core is maintained. We propose direct heating of the imploded core by the ultra-intense laser in the fast-ignition scheme. When the high pressure of imploded core plasma breaks the...
Mr
Vladimir Kornev
(Ioffe Institute)
10/16/14, 2:00 PM
Poster
The investigation of the behavior of fast ion (FI) is among the most important directions of research in the field of magnetic plasma confinement. Study the FI confinement in compact tokamak with relatively low toroidal magnetic field is topical in view of the increasing interest in developing neutron sources based on the nuclear fusion reactions. Capture efficiency of FI and thermalization...
Mr
Farhat Beg
(USA)
10/16/14, 2:00 PM
Poster
Recent experiments [1,2] and modeling [3,4] have shown that the large-scale preplasma significantly affects the laser-plasma interaction (LPI) dynamics and the resultant fast electron energy distribution, where the fast electron energies are much higher than the ones predicted by ponderomotive scaling due to additional stochastic acceleration in the low density region. We have carried out...
Mr
Chikang Li
(USA)
10/16/14, 2:00 PM
Poster
Understanding the physics responsible to the disagreement between experimental results and numerical simulations are of fundamental importance to inertial-confinement fusion (ICF) implosions, and particularly to the ignition-scale layered implosions currently taking place at the National Ignition Facility (NIF). The plasma kinetic effects, which have been overlooked in the conventional...
Dr
Akihiro Ishizawa
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Turbulent transport in finite-beta Large Helical Device (LHD) plasmas is investigated by means of electromagnetic gyrokinetic simulations. It is found that (i) the ITG mode growth rate decreases with increasing beta, and the kinetic ballooning mode (KBM) becomes a dominant instability for local beta values larger than 2-3% in typical LHD configurations, (ii) shearing between oppositely...
Dr
Zhe Zhang
(Osaka University)
10/16/14, 2:00 PM
Poster
The absolute energy transfer efficiency from laser to hot electrons in fast ignition plasma was estimated by applying quantitative high energy Kalpha x-ray spectroscopy. The absolute yield of Sn, Ta and Au Kalpha lines were measured by a calibrated Laue spectrometer. The Laue spectrometer was developed to cover the high energy Kalpha lines from Mo (Kalpha 17.48 keV) to Au (Kalpha: 68.80 keV)....
Dr
Kwan Chul Lee
(Korea, Republic of)
10/16/14, 2:00 PM
Poster
Understanding electron thermal transport is crucial for improving and predicting the confinement performance of future devices, e.g. FNSF and ITER. The observations of nonlocal electron thermal transport in tokamaks and stellarators challenge the standard local model of turbulence and transport. Here, we report the first observation of nonlocal electron thermal transport in a set of NSTX...
Dr
Yoshiro NARUSHIMA
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Dynamics of magnetic islands in helical plasmas has been studied by means of an externally imposed resonant magnetic perturbation (RMP) to clarify its effect on the MHD stability and confinement in the Large Helical Device (LHD) plasmas. It has been reported that spontaneous healing and growth of magnetic islands can be clearly separated on the space of plasma beta, collisionality and poloidal...
Mr
Shinsuke Fujioka
(Japan)
10/16/14, 2:00 PM
Poster
A series of experiments were carried out to evaluate energy coupling efficiency from a heating laser to a fuel core in the fast-ignition scheme of laser-driven inertial confinement fusion. Here we break down the efficiency, which is governed by enormous interactions and instabilities among intense laser, high-energy-density plasma, and relativistic electron beam (REB), into three measurable...
Dr
Junya Shiraishi
(Japan Atomic Energy Agency)
10/16/14, 2:00 PM
Poster
Extension of the kinetic-magnetohydrodynamic model is presented to include toroidal rotation shear effect for the first time. The sheared rotation is introduced through generalization of the guiding center Lagrangian, yielding two additional terms in a quadratic form of mode-particle resonance. These two terms are overlooked in conventional models. The new model is applied to stability...
Prof.
Hiroyuki Shiraga
(Institute of Laser Engineering, Osaka University)
10/16/14, 2:00 PM
Poster
Fast ignition (FI) experiments have been performed at the Institute of Laser Engineering, Osaka University by using Gekko-XII laser for implosion and LFEX laser for fast heating of fuel targets. In FI experiment with intense heating laser irradiation (>10^19 W/cm2), most of heating laser energy is converted to that of hot electrons with energy ranging well up to several 10 MeV. Intense hard...
Mr
Alexander Belokurov
(Ioffe Physical-Technical Institute, Saint Petersburg, Russian Federation)
10/16/14, 2:00 PM
Poster
Geodesic acoustic mode (GAM) is a specific mode of low-frequency oscillations in toroidal plasma, which does not participate in radial transport directly, although affects anomalous transport through control of turbulence level [1]. GAM-induced shear of radial electric field is not constant in time, therefore possibility of LH-transition initiating in this case is to be studied.
GAM were...
Prof.
Masakatsu Murakami
(Institute of Laser Engineering, Osaka University)
10/16/14, 2:00 PM
Poster
To achieve substantially high compression performance of the impact ignition, a novel compression scheme is proposed, in which hollow targets with specifically curved structures initially filled with uniform matter, are driven by converging shock waves. (i) Its self-similar dynamics is analyzed in detail. (ii) The dynamic behavior is demonstrated using two-dimensional hydrodynamic simulations....
Dr
Brian LaBombard
(MIT PSFC)
10/16/14, 2:00 PM
Poster
Parametric Decay Instabilities (PDI) have been linked to the sudden loss of superthermal electrons and current drive efficiency as the density is increased above a critical density n_crit in lower hybrid current drive experiments in Alcator C-Mod. Spectral peaks occur at multiples of the ion cyclotron frequency near the inner wall. As the density is increased to n_crit, the sidebands become...
Dr
Sumin Yi
(National Fusion Research Institute)
10/16/14, 2:00 PM
Poster
Understanding and prediction of turbulent transport are crucial to achieving improved confinement states in advanced magnetic fusion reactors. However, conventional transport models based on the local saturation paradigm fail to explain many experimental phenomena, e.g. the broken gyro-Bohm scaling, the stiffness of ion temperature profile etc. Nonlinear turbulence spreading in inhomogeneous...
Dr
Thomas W. Petrie
(USA)
10/16/14, 2:00 PM
Poster
Increasing input power and plasma current in present and future tokamaks naturally leads to more serious divertor and first wall heat flux problem, both for the steady state and the transient ELM heat deposition. Therefore, ELM control using the 3-D fields and peak heat flux reduction with divertor detachment must be compatible.
A large amount of deuterium (D2) gas is puffed into the lower...
Dr
Martin Wölz
(JENOPTIK Diode Lab GmbH)
10/16/14, 2:00 PM
Poster
The feasibility of inertial confinement fusion depends critically on the laser drivers. Advances in the light power density and the efficiency are still to be made. We present an overview of the fundamental limitations of laser diode arrays, which are used for pumping the solid state lasers, and show which steps the industry has taken so far in order to achieve the ambitious goals.
The pump...
Dr
Sergei Ryzhkov
(Bauman Moscow State Technical University)
10/16/14, 2:00 PM
ICC - Innovative Confinement Concepts
Poster
This paper presents a concept of dynamic plasma compression which unites a technique of megagauss magnetic field generation and methods of plasma confinement in a specially formed magnetic configuration. This concept is a determining one for the magneto-inertial (hybrid) approach to the controlled thermonuclear fusion. Comparing to the inertial confinement the main magneto-inertial fusion...
Dr
Sadayoshi Murakami
(Departement Nuclear Engineering, Kyoto University)
10/16/14, 2:00 PM
Poster
High ion temperature, T_i, experiments have been performed applying the tangential and perpendicular NBI heating systems in LHD. The high T_i plasma up to 7.3keV has been obtained during the decay phase of the density after rapid increase due to a carbon pellet injection. Simple heat transport analysis of these high T_i plasma has been done but the rapid change of density effect on the NBI...
Dr
Orso Meneghini
(Oak Ridge Associated Universities)
10/16/14, 2:00 PM
Poster
One Modeling Framework for Integrated Tasks (OMFIT) is a comprehensive integrated modeling framework developed to facilitate the interpretation of today experiments, enable theory validation, and support the design of next step devices. OMFIT is unique in its underlying data structure and grassroots approach. After only two years since the beginning of the project, the framework is now...
Mr
Xiaodi Du
(Japan)
10/16/14, 2:00 PM
Poster
Bursting resistive interchange modes destabilized by a characteristic motion of helically trapped energetic ions are for the first time observed in a helical plasma and induce large negative radial electric field near the edge, which indicates non-ambipolar losses of the fast ions by the modes. The burst modes also induce a clear change of toroidal plasma rotation and micro-turbulence...
Prof.
Atsushi Fukuyama
(Kyoto University)
10/16/14, 2:00 PM
Poster
In order to self-consistently describe the start-up phase of burning plasmas in the presence of energetic particles, we have developed a kinetic integrated tokamak modeling code TASK3G. This modeling is based on the behavior of the momentum distribution function of each particle species. The time evolution of the momentum distribution function is described by an advanced Fokker-Planck...
Mr
Anthony W. Leonard
(USA)
10/16/14, 2:00 PM
Poster
As magnetic confinement fusion research progresses toward the reactor scale, increasingly intense power exhaust threatens the integrity of plasma facing components. The compact nature, i.e., small major radius (R), of the spherical tokamak (ST) presents an economically attractive path to fusion commercialization, but magnifies the power exhaust challenge, because the plasma-wetted area is...
Dr
Pavel Cahyna
(Institute of Plasma Physics AS CR, v.v.i.)
10/16/14, 2:00 PM
Poster
Resonant magnetic perturbations (RMPs) can mitigate the edge-localized modes (ELMs), i.e. cause a change of the ELM character towards smaller energy loss and higher frequency. During mitigation a change of the spatial structure of ELM loads on divertor was observed on DIII-D and MAST: the power is deposited predominantly in the footprint structures formed by the magnetic perturbation. In the...
Dr
David Russell
(Lodestar Research Corporation)
10/16/14, 2:00 PM
Poster
The effect of lithium wall coatings on scrape-off-layer (SOL) turbulence is modeled with the Lodestar SOLT code to explore the implications for the SOL heat flux width on NSTX of experimentally observed, Li-induced changes in the pedestal profiles. The connection is important because pedestal profiles impact the overall fusion performance of ITER and future machines while the SOL heat flux...
Dr
Amanda Hubbard
(Massachusetts Institute of Technology, Plasma Science and Fusion Center)
10/16/14, 2:00 PM
Poster
I-Mode is a promising ELM-suppressed regime that combines H-mode-like energy confinement with L-mode-like particle and impurity transport. Key to its potential extrapolation to ITER and reactor regimes is the scaling of accessibility conditions and performance. The multi-machine experiments reported here, supported by the Pedestal and Edge Physics as well as Transport and Confinement ITPA...
Dr
Robert W. Harvey
(CompX)
10/16/14, 2:00 PM
Poster
The CQL3D Fokker-Planck code[1] has been upgraded to include physics of finite-orbit-width (FOW) guiding-center orbits[2,3], as compared with the previous zero-orbit-width (ZOW) model, and a recent first-order orbit calculation[2]. The Fast Ion Diagnostic FIDA[4,5] signal resulting from neutral beam (NBI) and high harmonic fast wave (HHFW) RF power injected into the NSTX spherical tokamak can...
Dr
Dennis Whyte
(MIT Plasma Science & Fusion Center)
10/16/14, 2:00 PM
Poster
Accelerator-based In-situ Material Surveillance (AIMS) is a novel technique for providing in-situ 2-D maps of the properties of plasma-facing surfaces in fusion devices, and has been successfully prototyped on the Alcator C-Mod tokamak [1]. AIMS adapts ion-beam analysis, the leading ex-situ material diagnostic tool, to the tokamak environment in order to provide quantitative non-destructive...
Mr
Theodore Golfinopoulos
(Plasma Science and Fusion Center, Massachusetts Institute of Technology)
10/16/14, 2:00 PM
Poster
Two new research tools - a Mirror Langmuir Probe (MLP) and a "Shoelace" antenna - have diagnosed and actively perturbed fluctuations in the Alcator C-Mod tokamak edge plasma. Both tools elucidate the physics associated with the Quasi-Coherent Mode (QCM, k_p~1.5/cm, f~50-200 kHz), the edge fluctuation responsible for the increased particle flux which sustains the steady-state Enhanced Dα...
Prof.
Liu Chen
(China)
10/16/14, 2:00 PM
Poster
In this work, nonlinear excitation of geodesic acoustic modes (GAM) by drift wave (DW) turbulence is investigated, taking into account effects of finite kinetic dispersiveness and system nonuniformities. The nonlinear equations describing nonlinear parametric decay of DW into GAM and DW lower sideband are derived using nonlinear gyrokinetic theory。 The corresponding governing equations are...
Prof.
Takashi Shimozuma
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
High harmonic Electron Cyclotron Resonance Heating (ECRH) is potential means of extending plasma density and beta-value ranges of fusion-relevant plasmas. Instead of the normally used fundamental ordinary (O1) and the second harmonic extraordinary (X2) modes, sufficient absorption can be expected using even O2 and X3 mode heating scenarios, when the temperature and density of a target plasma...
Dr
Riccardo De angelis
(Italy)
10/16/14, 2:00 PM
IFE - Inertial Fusion Experiments and Theory
Poster
The laboratory for inertial confinement fusion is dedicated to the study of laser produced plasmas in the 2 beams laser facility ABC, which can deliver up to 200 J in pulses of 3 nanosecond duration. The system is suitable for irradiating planar targets at I =10exp14-15 Wcm-2. This paper summarizes the main research programs brought forward in the last year.
Theoretical and experimental...
Mr
Alessio Morace
(Japan)
10/16/14, 2:00 PM
Poster
In the Fast Ignition scheme, the heating of the compressed Deuterium Tritium capsule is produced by a fast electron beam generated by an ultra-high intensity laser pulse, transporting the laser energy from the interaction region up to the compressed DT fuel and producing a one-sided hot spot, from which the thermonuclear burst propagates to the rest of the fuel.
In order to achieve ignition,...
Prof.
Noriyasu Ohno
(Nagoya University)
10/16/14, 2:00 PM
Poster
Recent study in the Large Helical Device (LHD) indicated that applying resonant magnetic perturbation (RMP) field is able to keep highly-radiating zone near the magnetic island X-point inside the ergodic region and particle flux onto the divertor plate is reduced accompanied by stable plasma detachment [1]. However, it is not clear yet where the particle flux starts to decrease in the RMP...
Dr
Satoshi Ohdachi
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
MHD activities in the region where the magnetic flux surfaces are disturbed by the externally applied field are now extensively studied in the context of the physics of ELM mitigation. Magnetic stochasticity plays important role as well in the high-beta experiment of the Large Helical Device (LHD), where topologically similar magnetic stochastic region is formed naturally outside the last...
Prof.
Umur Daybelge
(Istanbul Technical University)
10/16/14, 2:00 PM
Poster
The plasma rotation plays a central role in magnetic confinement of toroidal plasmas, as it can reduce turbulence and enhance transport. In turn rotation can be generated both intrinsically by microturbulence via Reynolds stress, and by external momentum sources, such as, for example, neutral beam injection (NBI). By assuming a collisional plasma with steep gradients at the edge region of an...
Dr
Laurent COLAS
(CEA, IRFM)
10/16/14, 2:00 PM
Poster
In magnetic Fusion devices, non-linear wave-plasma interactions in the plasma edge often set operational limits for Radio-Frequency (RF) heating systems, due to impurity production or excessive heat loads. Understanding these interactions is key for reliable high-power Ion Cyclotron (IC) wave launch over long pulses in all-metal devices. Edge IC losses are attributed to a Direct Current (DC)...
Prof.
Abdelaziz Sid
(PRIMALAB laboratory, University of Batna)
10/16/14, 2:00 PM
Poster
In this work, the Weibel instability due to inverse bremsstrahlung (IB) absorption in laser fusion plasma has been investigated. The stabilization effect due to the coupling of the self-generated magnetic field by Weibel instability with the laser wave field is explicitly showed. In this study, the relativistic effects are taken into account where the basic equation is the relativistic...
Dr
Mamoru Shoji
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Dust transport study in magnetic plasma confinement devices has been attracting attention because it is concerned that dusts influence main plasma performances in nuclear fusion reactors. Exfoliated dusts consisting of accumulated impurity deposition layers can enter the main plasma to enhance impurity radiation.
The Large Helical Device (LHD) is a unique test stand for studying the dust...
Dr
Keisuke Fujii
(Kyoto university)
10/16/14, 2:00 PM
Poster
The radial distribution of the neutral hydrogen atom density (n_H) and pressure (P_H) in the Large Helical Device (LHD) is studied. The n_H distribution is determined from a detailed analysis of the intensity-calibrated Balmer-alpha line profile while the P_H distribution is obtained with a simple one-dimensional analytical model. We have for the first time determined n_H at the center of a...
Mr
Yi Tan
(Tsinghua University)
10/16/14, 2:00 PM
Poster
The coupling between Alfven waves and plasmas are studied before applying high power rf waves to drive current in the SUNIST spherical tokamak (R/a: 0.3 m/0.23 m; B_T0: 0.15 T; I_P: 30~70 kA; n_e: ~1E19 m^-3; pulse length: 10~25 ms). The impedance of antennas reflects the coupling and can be easily obtained from the rf voltage across and the rf current through the antennas since the...
Prof.
Shigeru Sudo
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
By injecting tracers into the LHD plasma with a tracer-encapsulated solid pellet (TESPEL) method, we found that the impurity source location is essential for determining the impurity transport property. The impurity transport for three different locations of impurity source are studied by (i) thick-shell-type TESPEL (thickness of ~240 micron m), (ii) thin-shell-type TESPEL (thickness of ~75...
Prof.
Mikhail Shmatov
(Ioffe Physical Technical Institute)
10/16/14, 2:00 PM
Poster
The use of the D-D fusion reactions for power production is discussed for many years. The main advantage of the power plants employing these reactions consists in a lower amount of tritium involved in the process. Ignition of the D-D fusion reactions is a more difficult task compared to the ignition of the D-T fusion reaction. For power plants with the magnetic plasma confinement, the use of...
Dr
Rajesh Maingi
(Princeton Plasma Physics Laboratory)
10/16/14, 2:00 PM
Poster
The role lithium wall conditioning on the achievement of high performance, long pulse discharges in NSTX and EAST is documented. Common observations include a reduction in hydrogenic recycling, confinement enhancement, and the elimination of ELMs. The plasma confinement and pulse length in both devices improve with increasing lithium conditioning. In NSTX, the impurity accumulation which...
Prof.
ZHIWEI Ma
(IFTS,ZHEJIANG)
10/16/14, 2:00 PM
Poster
In this work, we present analytical and simulation results of the wave and energetic particle (EP) dynamics associated with Alfvén Eigenmodes (AE) in tokamak fusion plasmas. It is found that (i) both the nonlinear saturation and the wave-frequency chirping dynamics of toroidal Alfvén eigenmodes (TAE) depend crucially on the EP velocity anisotropy, and exhibits features of wave-EP...
Prof.
Brian Nelson
(USA)
10/16/14, 2:00 PM
Poster
Transient Coaxial Helicity Injection (CHI) in the National Spherical Torus Experiment (NSTX) has generated toroidal current on closed flux surfaces without the use of the central solenoid. When induction from the solenoid was added, CHI initiated discharges in NSTX achieved 1 MA of plasma current using 65% of the solenoid flux of standard induction-only discharges. CHI is incorporated into the...
Dr
Gakushi Kawamura
(National Institute for Fusion Science)
10/16/14, 2:00 PM
Poster
Transport of plasma, neutral and impurities in peripheral regions is closely linked to the configuration of the device. The divertor configuration of LHD (Large Helical Device) has been modified to the closed one to control neutral transport and achieve effective pumping. In order to make comparisons of the open and the closed LHD divertor, a new calculation mesh covering the ergodic, the...
Dr
Jozef ONGENA
(Plasma Physics Lab, ERM-KMS, Brussels)
10/16/14, 2:00 PM
Poster
An ICRH antenna consisting of two poloidal straps is now under design for W7-X in a collaboration between IEK-4/FZJ and LPP/ERM-KMS. The two straps are on one side connected to a tuning capacitor and grounded to the antenna box at the other end. To reduce the voltage in the feeding transmission lines and matching system, a pre-matching has been implemented by connecting the RF transmission...
