A5026578397- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Geophysics and Gravity Measurements
- Nuclear Materials and Properties
- Gyrotron and Vacuum Electronics Research
- High-pressure geophysics and materials
- Fluid Dynamics and Turbulent Flows
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Vacuum and Plasma Arcs
- Atomic and Subatomic Physics Research
- Spacecraft and Cryogenic Technologies
- Pulsed Power Technology Applications
- Cold Fusion and Nuclear Reactions
- Engineering Applied Research
- Astro and Planetary Science
- Radiative Heat Transfer Studies
- Real-time simulation and control systems
Max Planck Institute for Plasma Physics
2016-2025
CEA Cadarache
2020-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2020-2024
Institut de Recherche sur la Fusion par Confinement Magnétique
2021-2024
Aix-Marseille Université
2013-2024
Centre National de la Recherche Scientifique
2013-2024
Max Planck Society
2016-2021
Royal Military Academy
2020
Culham Science Centre
2017
Physique des interactions ioniques et moléculaires
2017
Abstract The ramp-up is a critical phase in the operations of Tokamak, during which engineering and physics aspects must be taken into account to ensure stability, minimize flux consumption avoid disruptions. Predicting phases faces challenges such as nonlinearity, uncertainty on boundary initial conditions changes magnetic equilibrium. Our work uses High-Fidelity Pulse Simulator (HFPS), Python workflow based JINTRAC. input output are machine code generic IMAS data format. HFPS predicts...
Abstract Progress in physics understanding and theoretical model development of plasma transport confinement (TC) the ITPA TC Topical Group since publication ITER Physics Basis (IPB) document (Doyle et al 2007 Nucl. Fusion 47 S18) was summarized focusing on contributions to burning prediction control. This paper provides a general streamlined overview advances that were mainly led by joint experiments activities for last 15 years (see JEX/JA table appendix). starts with scientific strategy...
Abstract The influence of rotation, collisionality and trapped particle fraction on the magnitude direction neoclassical impurity transport in tokamaks is analyzed using an extensive database drift-kinetic simulations with NEO code. It shown that operational window opens at sufficiently high Mach number low collisionality, where temperature screening impurities increases higher rotation. If increases, this effect quickly lost gradient then drives inward flux when rotation present. boundary...
This paper outlines an approach towards improved rigour in tokamak turbulence transport model validation within integrated modelling. Gaussian process regression (GPR) techniques were applied for profile fitting during the preparation of modelling simulations allowing rigourous sensitivity tests prescribed initial and boundary conditions as both fit derivative uncertainties are provided. was demonstrated by a JETTO simulation JET ITER-like-wall H-mode baseline discharge #92436 with QuaLiKiz...
Abstract Using a recently installed impurity powder dropper (IPD), boron (<150 μ m) was injected into lower single null (LSN) L-mode discharges in WEST. IPDs possibly enable real-time wall conditioning of the plasma-facing components and may help to facilitate H-mode access full-tungsten environment The this experiment featured I p = 0.5 MA, B T 3.7 T, q 95 4.3, t pulse 12–30 s, n e,0 ∼ 4 × 10 19 m −2 , P LHCD 4.5 MW. Estimates deuterium particle fluxes, derived from combination visible...
Abstract The full W environment that is now foreseen for ITER puts strong emphasis on experimental results obtained in present devices similar conditions. In this context, the WEST tokamak well equipped to bring key contributions preparation of operation, thanks its capability perform long pulses dominant electron heating, torque-free scheme based RF systems, and ITERgrade actively cooled divertor. Recent interest cover understanding tungsten contamination evaluation conditioning methods,...
Abstract A new record was set on the WEST Tokamak, designed to operate long duration plasmas in a tungsten (W) environment, with an injected energy of 1.15 GJ and plasma 364 s. Scenario development supported by integrated modeling using High Fidelity Plasma Simulator (HFPS), European IMAS-coupled version JETTO/JINTRAC, which integrates physics-driven modules into unified framework. In particular, reduced model for Lower-Hybrid heating Current-Drive (LHCD) quasi-linear turbulent transport...
Upgraded spectroscopic hardware and an improved impurity concentration calculation allow accurate determination of boron density in the ASDEX Upgrade tokamak. A database measurements is compared to quasilinear nonlinear gyrokinetic simulations including Coriolis centrifugal rotational effects over a range H-mode plasma regimes. The peaking measured profiles shows strong anti-correlation with rotation gradient, via relationship explained reproduced by theory. It demonstrated that...
Abstract In the full tungsten environment of WEST, during its first phase operation, around 25% pulses exhibited a rapid central electron temperature collapse. phase, WEST plasmas were mostly heated by lower hybrid current drive (LHCD) and ion cyclotron resonance heating (ICRH). this publication, collapsing are analysed to understand key actuators at play. Experimentally, an initial slow reduction due density increase is observed, while profile flat constant in time. Then, radiative collapse...
Abstract The physics governing the collisional transport of impurities in tokamak plasmas can change significantly depending on four main parameters, namely collisionality, impurity charge and mass, trapped particle fraction, which vary widely from core to edge a fusion device. We present an analytical model for with consistent dependence broad scans these showing good agreement drift-kinetic code NEO. Radial profiles fluxes are calculated different species using ASDEX Upgrade experimental...
Tungsten transport is investigated in WEST long pulse L-mode plasmas operated with the strike point on actively cooled upper tungsten divertor. The pulses are mostly heated by lower hybrid waves. It experimentally found that does not centrally accumulate throughout these ∼ 30 s reproducible discharges despite large normalised electron density gradients . To explain observations, turbulent and neoclassical of electrons ions computed GKW Peeters A.G. et al (2009 Computer Phys. Commnun. 180...
Abstract Achieving a successful plasma current ramp-up in full tungsten tokamak can be challenging due to the large core radiation (and resulting low temperature) that faced with this heavy metallic impurity if its relative concentration is too high. Nitrogen injection during of WEST discharges greatly improves temperature and magnetohydrodynamic (MHD) stability. Experimental measurements integrated simulations RAPTOR code, complemented QuaLiKiz neural network for computing turbulent...
The collisional stabilisation via energy scattering and pitch-angle of micro-instabilities in tokamak plasmas is investigated by means gyrokinetic simulations with a special emphasis on the often neglected operator. It shown that linear regime has negligible effect Ion Temperature Gradient (ITG) modes but enhances Trapped Electron Modes (TEM) presence nonzero ion temperature density gradients. This sensitive to model used for restoring term collision contributions parallel drift motion total...
The presence of helium is fundamentally connected to the performance a fusion reactor, as fusion-produced expected heat plasma bulk, while He 'ash' accumulation dilutes fuel.An understanding transport via experimentally validated theoretical models low-Z impurity turbulent indispensable predict density profile in future devices.At ASDEX Upgrade, detailed, multi-species investigations have been undertaken dedicated experiments, resulting an extensive database and boron profiles over wide...
Abstract Reduced quasilinear and nonlinear (gradient-driven) models with scale separations, commonly used to interpret experiments forecast turbulent transport levels in magnetised plasmas, are tested against without separations (flux-driven). Two distinct regimes of turbulence—either above threshold or near marginal stability—are investigated Boltzmann electrons. The success reduced hinges particular on the reproduction fluxes. Good agreement between is found threshold, whilst significantly...
Abstract WEST L-mode plasmas with dominant electron heating and no core torque source have observed improvements in confinement during boron (B) powder injection. These results are reminiscent of previous injection experiments on other devices gaseous impurity seeding WEST. During injection, the stored energy increased up to 25% due enhanced ion heat particle confinement. The were not indicative an L-H transition. To identify mechanisms causality chain behind these confinement, we employ...
A gyro-kinetic analysis of intrinsic rotation is presented for the ASDEX Upgrade tokamak. The turbulence code, GKW and neoclassical transport NEO are coupled so that equilibrium distribution function included in background simulation. This implementation benchmarked against a similar GS2 (Dorland et al 2000 Phys. Rev. Lett. 85 5579) analytical predictions.
A series of experimental observations light impurity profiles was carried out in JET (Joint European Torus) ITER-like wall (ILW) L-mode plasmas order to investigate their transport mechanisms. These discharges feature the presence 3He, Be, C, N, Ne, whose measured by active Charge Exchange diagnostics are compared with quasi-linear and non-linear gyro-kinetic simulations. The peaking 3He density follows electron peaking, Be Ne also peaked, while C N flat mid plasma region. Gyro-kinetic...
Previous studies (e.g. (Kappatou 2019 Nucl. Fusion 59 056014)) have shown that discrepancies exist between experimental and modelled light impurity peaking in specific regimes. In particular, NBI heated plasmas, the strong hollowness of boron profiles are not captured by modelling. this context, a dedicated ASDEX Upgrade discharge, including helium density measurements, is studied where such appear. Emphasis given to impact fast ions on turbulent neoclassical transport computed with codes...
ASDEX Upgrade plasmas fuelled by pellets in the H-mode confinement regime are analyzed. The gyrokinetic code GKW is applied to calculate microinstabilities which predicted be unstable these plasmas. Two types of density gradient driven modes found, outside and inside pellet deposition location. first mode a negative radial gradient, corresponds usual trapped electron instability, producing large diffusive particle flux directed outwards, becomes more with increasing fraction decreasing...
Abstract High power experiments, up to 9.2 MW with LHCD and ICRH, have been carried out in the full tungsten tokamak WEST. Quasi non inductive discharges achieved allowing extend plasma duration 53 s stationary conditions particular respect contamination. Transitions H mode are observed, H-modes lasting 4 obtained. The increase stored energy is weak since crossing separatrix close L–H threshold. Hot L plasmas (central temperature exceeding 3 keV) a confinement time following ITER L96 scaling...
The impact of the change mass hydrogen isotopes on turbulent particle flux is studied. trapped electron component convection induced by collisionality, which outward in ion temperature gradient turbulence, increases with decreasing thermal velocity isotope. Thereby, lighter isotope, stronger pinch, and larger predicted density at null flux. passing isotope can also affect gradient. This effect however subdominant for usual core plasma parameters. analytical results are confirmed means both...