A5073462390- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Nuclear Materials and Properties
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Geophysical and Geoelectrical Methods
- Geophysical Methods and Applications
- Nuclear Physics and Applications
- Glaucoma and retinal disorders
- Retinal Imaging and Analysis
- Nuclear Engineering Thermal-Hydraulics
- Seismic Waves and Analysis
- Retinal Diseases and Treatments
- Non-Destructive Testing Techniques
- Corneal surgery and disorders
- Intraocular Surgery and Lenses
- Advancements in Semiconductor Devices and Circuit Design
- Reservoir Engineering and Simulation Methods
- Fuel Cells and Related Materials
- Atomic and Molecular Physics
CEA Cadarache
2001-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2001-2024
Direction des énergies
2006-2020
University of Liège
2013-2018
KU Leuven
2017
Centre Hospitalier Universitaire de Saint-Étienne
2007-2013
Université Claude Bernard Lyon 1
2010
Neuropsychiatrie : Recherche Epidemiologique et Clinique
2007
California Institute of Technology
1998
Joint European Torus
1996
The onset of a neoclassical tearing mode (NTM) depends on the existence large enough seed island. It is shown in Joint European Torus that NTMs can be readily destabilized by long-period sawteeth, such as obtained sawtooth stabilization from ion-cyclotron heating or current drive. This has important implications for burning plasma scenarios, alpha particles strongly stabilize sawteeth. also that, adding and drive just outside inversion radius, sawteeth are destabilized, resulting shorter...
Third-harmonic ion-cyclotron-resonance heating of ${}^{4}\mathrm{He}$-beam ions has produced for the first time on JET tokamak high-energy populations ${}^{4}\mathrm{He}$ to simulate 3.5 MeV fusion-born alpha (\ensuremath{\alpha}) particles. Acceleration energy range is confirmed by \ensuremath{\gamma}-ray emission from nuclear reaction ${}^{9}\mathrm{Be}(\ensuremath{\alpha},n\ensuremath{\gamma}){}^{12}\mathrm{C}$ and excitation Alfv\'en eigenmodes. Concomitant electron sawtooth...
Upgrade of the Tore Supra ergodic divertor (ED) has led to significant progress in ED physics. Pulse durations 30?s with LHCD have been achieved demonstrating heat exhaust capability both actively cooled technology at hand and this specific concept. The disruptive limit governed by stochastization outer magnetic surfaces is found occur for a value Chirikov parameter reaching two on surface q = 2+(3/12). This experimentally observed robustness allows one operate very low safety factor...
To alleviate the plasma-wall interaction problems in magnetic confinement devices, a stochastic layer is used at edge of Tore Supra tokamak (ergodic divertor). A very important point to determine power deposition on plasma facing components. Two different kinds transport can be identified such configuration: surrounding confined plasma, with random walk process, and scrape-off (SOL) like transport, laminar near The regime investigated terms simple criterion, namely that proportional radial...
A systematic study of the thermal behaviour ion cyclotron range frequencies (ICRF) antenna front faces was undertaken on Tore Supra tokamak over two years plasma operation, by means infrared (IR) and visible light cameras. Among variety edge-antenna interaction phenomena observed experimentally, present paper focuses most deleterious effect for ICRH a non-resonant radio-frequency (RF) process causing hot spots Faraday screen bursts metallic impurities. The phenomenology (time history,...
Plasmas heated by ICRF only in the JET tokamak show distinct structures toroidal rotation profile, with regions where dω/dr>0 when minority cyclotron resonance layer is far off-axis. The dominantly co-current a clear off-axis maximum. There slight difference between high-field side (HFS) or low-field position of this layer: maximum profile modestly higher for HFS position. This contrast to predictions theories that rely mainly on effects arising from ICRF-driven fast ions account...
Ion cyclotron resonance frequencies (ICRF) mode conversion has been developed for localized on-axis and off-axis bulk electron heating on the JET tokamak. The fast magnetosonic waves launched from low-field side ICRF antennas are mode-converted to short-wavelength high-field of 3He ion layer in D 4He plasmas subsequently damped electrons. resulting power deposition, measured using modulation, is narrow with a typical full-width at half-maximum ≈30 cm (i.e. about 30% minor radius) total...
Abstract The diffusion and the exponential divergence of neighbouring trajectories which characterize stochastic magnetic field are reviewed. effect these properties on heat current transport leads to an increase radial diffusivity a reduction toroidal electric conductivity. finite connection length wall in perturbed layer determines regular particle deposition pattern.
A new scenario to delay or prevent neoclassical tearing mode (NTM) onset is presented. By active sawtooth destabilization, short period and low amplitude sawteeth are generated, such that the produced NTM seed island reduced threshold normalized plasma pressure for triggering of NTMs, βNonset, increased. The has been explored experimentally in Joint European Torus (JET). Ion cyclotron resonance frequency (ICRF) waves tuned 2nd harmonic H-minority have used control. Whereas ICRF generally...
Ion cyclotron range of frequencies (ICRF) heating experiments with the third harmonic deuterium resonance in plasma centre have been carried out at JET. These were first to demonstrate damping on initially Maxwellian plasmas. A record deuterium-deuterium (DD) fusion reaction rate for ICRF-only JET was achieved. The discharges simulated PION code (a self-consistent calculation evolution distribution function and ICRF power deposition). To obtain reasonable agreement between measurements...
The toroidal field coils in Tore Supra are supra-conducting, and their number is restricted to 18. As a result, the ripple fairly large, about 7% at plasma boundary. has consequently been equipped with dedicated loss diagnostics, which allowed studies. This paper reports on measurements made these diagnostics provides an analysis of experimental results, comparing them theoretical expectations whenever possible. Furthermore, main heating source accelerating ions ion cyclotron resonance range...
Ion cyclotron heating and current drive at ω≈2ωcH in JET deuterium plasmas with a hydrogen concentration nH/(nD+nH) the range of 5–15% are analysed, comparing results numerical computer modelling experiments. Second harmonic damping is found to be maximized by placing resonance on low-field side (LFS) torus, which minimizes competing direct electron parasitic high-harmonic D presence beams. The shape calculated perturbation radial localization power density for LFS consistent experimentally...
Radial particle transport is considered in a plasma with ergodic and stochastic flux lines. The self-consistent electric field neglected the due to succession of mass convections along lines, series very small-scale-length transverse diffusion between neighboring dependence average radial on thermodynamic forces, namely pressure gradient that controls parallel convection, density small-scale investigated. conditions for which driven by or are derived.
In burning plasma experiments, the very energetic alpha (α) particles resulting from a deuterium–tritium fusion reaction will be dominant heating mechanism and give rise to new physics issues. Recent experiments performed on Joint European Torus [P. H. Rebut B. E. Keen, Fusion Technol. 11, 13 (1987)] aiming investigate are reported in this paper. presence of particles, magnetohydrodynamic stability plasmas is affected. Sawteeth strongly stabilized may lead onset neoclassical tearing modes...
Fast wave current drive (FWCD) experiments have been performed in JET plasmas with electron internal transport barriers produced LHCD. Because of a large fraction parasitic absorption, owing to weak single pass damping, the inductive nature plasma and interplay between RF-driven bootstrap only small changes are seen central profiles. The measured difference density for co- counter-current is larger than response expected from diffusion calculations, but smaller driven currents, suggesting...