J.F. Artaud
A5071512572- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Stability and Controllability of Differential Equations
- Dust and Plasma Wave Phenomena
- Titanium Alloys Microstructure and Properties
- Edible Oils Quality and Analysis
- Earthquake and Tsunami Effects
- Numerical methods for differential equations
- Gas Dynamics and Kinetic Theory
- Power System Optimization and Stability
- Electrostatic Discharge in Electronics
- Advanced Data Storage Technologies
- Computational Physics and Python Applications
- Quantum chaos and dynamical systems
- Metal and Thin Film Mechanics
- Electromagnetic Launch and Propulsion Technology
- Wave and Wind Energy Systems
CEA Cadarache
2013-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2013-2023
Max Planck Institute for Plasma Physics
2023
Institut de Recherche sur la Fusion par Confinement Magnétique
2021
Hôpital Gui de Chauliac
2014
DSM (Netherlands)
2013
Fusion Academy
2008
Fusion (United States)
2008
Abstract In 2021 JET exploited its unique capabilities to operate with T and D–T fuel an ITER-like Be/W wall (JET-ILW). This second major campaign (DTE2), after DTE1 in 1997, represented the culmination of a series enhancements—new fusion diagnostics, new injection capabilities, refurbishment plant, increased auxiliary heating, in-vessel calibration 14 MeV neutron yield monitors—as well as significant advances plasma theory modelling community. DTE2 was complemented by sequence isotope...
Abstract For the past several years, JET scientific programme (Pamela et al 2007 Fusion Eng. Des . 82 590) has been engaged in a multi-campaign effort, including experiments D, H and T, leading up to 2020 first with 50%/50% D–T mixtures since 1997 ever plasmas ITER mix of plasma-facing component materials. this purpose, concerted physics technology was launched view prepare campaign (DTE2). This paper addresses key elements developed by directly contributing preparation. intense preparation...
Abstract WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up 1000 s. In support of ITER operation and DEMO conceptual activities, key missions are: (i) qualification high heat flux plasma-facing components integrating both technological physics aspects relevant particle exhaust conditions, particularly for the monoblocks foreseen divertor; (ii) integrated steady-state at confinement, with a focus on power issues. During phase...
Abstract Since the last IAEA Fusion Energy Conference in 2018, significant progress of experimental program HL-2A has been achieved on developing advanced plasma physics, edge localized mode (ELM) control physics and technology. Optimization confinement performed. In particular, high- β N H-mode plasmas exhibiting an internal transport barrier have obtained (normalized pressure reached up to 3). Injection impurity improved confinement. ELM using resonance magnetic perturbation or injection a...
Integrated simulations are performed to establish a physics basis, in conjunction with present tokamak experiments, for the operating modes International Thermonuclear Experimental Reactor (ITER). Simulations of hybrid mode done using both fixed and free-boundary 1.5D transport evolution codes including CRONOS, ONETWO, TSC/TRANSP, TOPICS ASTRA. The is simulated GLF23 CDBM05 energy models. injected powers limited negative ion neutral beam, cyclotron electron heating systems. Several plasma...
Self-consistent transport simulation of ITER scenarios is a very important tool for the exploration operational space and scenario optimisation. It also provides an assessment compatibility developed (which include fast transient events) with machine constraints, in particular poloidal field (PF) coil system, heating current drive (H&CD), fuelling particle energy exhaust systems. This paper discusses results predictive modelling all reference variants using two suite linked equilibrium...
Abstract This paper explores the operational boundaries and power availability of neutral beam injection (NBI) system in ITER, with a specific focus on shine-through loss prevention. Shine-through, phenomenon where part injected remains un-ionized plasma directly impacts first wall components, poses significant risk to lifetime ITER’s plasma-facing components. The window for NBI is consequently constrained by these losses, which are influenced factors such as density, energy, geometry....
Aimed at high-confinement (H-mode) plasmas in the Experimental Advanced Superconducting Tokamak (EAST), effect of local gas puffing from electron and ion sides a lower hybrid wave (LHW) antenna on LHW–plasma coupling high-density experiments with current drive (LHCD) are investigated EAST. results show that side is more favourable to improve compared side. Investigations indicate without affected by density near LHW grill (grill density), hence leading multi-transition low–high–low (L–H–L)...
Particle transport has been studied in the Tore Supra tokamak by using modulated ion cyclotron resonance heating to generate perturbations of density and temperature. For first time, a reversal particle convective velocity strong increase turbulent flux have clearly observed. When mixed critical gradient ${\ensuremath{\zeta}}_{c}=R/{L}_{T}+4(R/{L}_{n})=22$ is exceeded, increases sharply reverses from inward outward. These observations are agreement with quasilinear, gyrokinetic calculations....
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...
Hybrid scenario performance in ITER is studied with the CRONOS integrated modelling suite, using GLF23 anomalous transport model for heat prediction. predicted core confinement optimized through tailoring q -profile shape by a careful choice of current drive actuators, affecting due to dependence turbulence level on absolute values and magnetic shear. A range various heating choices are examined, as different assumptions pedestal height. The optimum be one that maximizes ratio s / throughout...
The NEMO (NEutral beam MOdelling) code for simulating neutral ionization during injection (NBI) in tokamak plasmas has been developed implementation integrated modelling frameworks and is presented. Integrated of fusion becoming increasingly important, both preparation analysis experiments large devices. Moreover, it should play a crucial role the design future reactors. In modern context, requires codes that are (i) flexible terms their interfaces, i.e. can be adapted different simulation...
A real-time model-based controller is developed for the tracking of distributed safety-factor profile in a tokamak plasma.Using relevant physical models and simplifying assumptions, theoretical stability robustness guarantees were obtained using Lyapunov function.This approach considers couplings between poloidal flux diffusion equation, time-varying temperature profiles an independent total plasma current control.The actuator chosen safety factor Lower Hybrid Current Drive, although results...
Extensive experimental data support reliable power deposition and current drive by lower-hybrid (LH) waves in conditions where a large spectral gap exists between the nominal parallel index of refraction prescribed antenna characteristics phasing, that required for significant Landau damping to take place. We argue only modification initial spectrum at plasma edge could explain observations. Based on this assumption, new prescription simulations LH using ray-tracing Fokker-Planck modelling...
A real-time capable core turbulence tokamak transport model is developed. This constructed from the regularized nonlinear regression of quasilinear gyrokinetic code output. The performed with a multilayer perceptron neural network. input for network training set consists five dimensions, and limited to adiabatic electrons. successfully reproduces fluxes predicted by original model, while gaining orders magnitude in computation time. implemented simulator, simulates 300s ITER discharge 10s....
The "European Transport Simulator" (ETS) [1,2] is the new modular package for 1-D discharge evolution developed within EFDA Integrated Tokamak Modelling (ITM) Task Force.It consists of precompiled physics modules combined into a workflow through standardized input/output data-structures.Ultimately, ETS will allow an entire simulation from start up until current termination phase, including controllers and sub-systems.The paper presents status towards this ultimate goal.It discusses design...
Improvement (up to a factor of approximately 4) the electron-cyclotron (EC) current drive efficiency in plasmas sustained by lower-hybrid (LH) has been demonstrated stationary conditions on Tore Supra tokamak. This was made possible feedback controlled discharges at zero loop voltage, constant plasma current, and density. effect, predicted kinetic theory, results from favorable interplay velocity space diffusions induced two waves: EC wave pulling low-energy electrons out Maxwellian bulk, LH...
Steady state full noninductive current tore supra plasmas offer a unique opportunity to study the local parametric dependence of particle pinch velocity, in order discriminate among different theories. Magnetic field shear is found generate an inward which dominant gradient region (normalized radius 0.3</=r/a</=0.6). In contrast, direction plasma core (r/a</=0.3) correlated with electron temperature length. The results are agreement both turbulent theoretical and computational predictions.
MHD instabilities driven by fast electrons identified as fishbonelike modes have been detected on Tore Supra during lower hybrid current drive discharges. Direct experimental evidence is reported of a novel feature: the regular redistribution suprathermal toward external tokamak regions which are correlated to periodic mode frequency jumps. Sharp drops electron temperature time trace factually linked cyclical deterioration confinement.
Abstract HL-2M is a new medium-sized tokamak under construction at the Southwestern Institute of Physics, dedicated to supporting critical physics and engineering issues ITER CFETR. Analyzing integrated plasma scenarios essential for assessing performance metrics foreseeing as well envisaged experiments HL-2M. This paper comprehensively presents kind expected discharge regimes (conventional inductive (baseline), hybrid steady-state) based on suite codes METIS. The simulation results show...
Abstract The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with focus on testing the ITER actively cooled W divertor tokamak conditions. Following successful completion phase 1 (2016-2021), 2 started December 2022 lower made entirely ITER-grade mono-blocks. A boronization prior first plasma attempt allowed smooth startup new divertor. Despite reduced...
Electron and impurity transport has been studied in sawtoothing plasmas the Tore-Supra tokamak. High time space resolution measurements of electron density reveal existence a flat profile region encompassing q = 1 surface, on which is superimposed peak building up between sawtooth relaxations. For first this regime, we have determined underlying both nickel electrons independently effect sawteeth central part plasma. consistent with neoclassical expectations only close vicinity magnetic...
Experiments to study inward heat transport phenomena have been performed in the Tore Supra tokamak with off-axis electron cyclotron resonance heating (ECRH). Both power balance and perturbation analysis done for low-frequency (1 Hz) ECRH modulation experiments. Heat diffusivity pinch separately determined by fitting experimental data of amplitude phase Fourier transform modulated temperature a linear model including convection term. Comparison critical gradient has shown that previously...
This paper shows that semi-empirical data-driven models based on a two-time-scale approximation for the magnetic and kinetic control of advanced tokamak (AT) scenarios can be advantageously identified from simulated rather than real data, used design. The method is applied to combined safety factor profile, q(x), normalized pressure parameter, βN, using DIII-D parameters actuators (on-axis co-current neutral beam injection (NBI) power, off-axis NBI electron cyclotron current drive ohmic...
Lower hybrid (LH) assisted plasma current ramp-up in ITER is demonstrated using a free-boundary full tokamak discharge simulator which combines the DINA-CH and CRONOS codes. LH applied from initial phase of increases safety margins operating superconducting poloidal field coils both by reducing resistive ohmic flux consumption providing non-inductively driven current. Loss vertical control associated with high internal inductance avoided tailoring density profiles. Effects early application...