A5024360356- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Lightning and Electromagnetic Phenomena
- Nuclear reactor physics and engineering
- Electromagnetic Simulation and Numerical Methods
- Antenna Design and Analysis
- Welding Techniques and Residual Stresses
- Antenna Design and Optimization
- Metal and Thin Film Mechanics
- Metallurgical Processes and Thermodynamics
- Microstructure and Mechanical Properties of Steels
- Full-Duplex Wireless Communications
- Advanced materials and composites
- Electromagnetic Scattering and Analysis
- Semiconductor materials and interfaces
- Anomaly Detection Techniques and Applications
- Fault Detection and Control Systems
- High-pressure geophysics and materials
- Pulsed Power Technology Applications
- Nuclear Materials and Properties
Max Planck Institute for Plasma Physics
2023-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2017-2024
Institut Jean Lamour
2019-2024
Centre de Gestion Scientifique
2024
Centre National de la Recherche Scientifique
2019-2024
Université de Lorraine
2017-2024
CEA Cadarache
2017-2024
Chinese Academy of Sciences
2017-2023
Institute of Plasma Physics
2017-2022
Institut de Recherche sur la Fusion par Confinement Magnétique
2020-2022
Abstract For successfully heating plasma with waves in the Ion Cyclotron Range of Frequencies (ICRF), mitigating impurity production is just as crucial maximizing power coupling, especially high-Z environments [Urbanczyk 2021]. Only when coupled limited influence on production, can ICRF truly become a powerful tool to directly deposit energy ions, modify turbulence-driven transport and enhance efficiency fusion reactions. 
To do so, one must rely toroidal array at least three active...
In this paper we validate the finite element code RAPLICASOL, which models radiofrequency wave propagation in edge plasmas near ICRF antennas, against calculations with TOPICA code. We compare output of both codes for ASDEX Upgrade 2-strap antenna, and a 4-strap WEST-like antenna. Although RAPLICASOL requires considerably fewer computational resources than TOPICA, find that predicted quantities experimental interest (including reflection coefficients, coupling resistances, - -matrix entries,...
Abstract As part of ITPA-Integrated Operational Scenario activities, this contribution reviews recent experimental characterizations radio-frequency (RF)-induced scrape-off layer (SOL) modifications various tokamaks worldwide and the LArge Plasma Device at UCLA. The phenomenology, as observed using a large variety measurement techniques, is consistent with expectations from RF sheath rectification. Emphasis then put on complex three-dimensional (3D) spatial patterns RF–SOL interaction, in...
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...
Three identical new WEST Ion Cyclotron Resonance Heating (ICRH) antennas have been designed, assembled then commissioned on plasma from 2013 to 2019.The ICRH system is both load-resilient and compatible with long-pulse operations.The three successfully operated together in 2019 2020.The load resilience capability has demonstrated the antenna feedback controls for phase matching developed.The breakdown detection systems validated protected antennas.The use of combination Lower Hybrid...
Abstract Experimental verification of ion cyclotron range frequencies (ICRF) wave coupling is crucial to gain insight into the physics improvement ICRF antenna coupling. The progress experiments on EAST has been reported since 2007. dependence loading resistance target plasma parameters, operational regimes and synergic heating scenarios are reviewed. Results show that R c in L-mode regime meets relation ∝ exp(−1.5 k ∥ x ), which good agreement with simulation results a perfectly matched...
Abstract Experimental data, together with interpretive modeling tools, are examined to study trends in the tungsten (W) source all-W environment of WEST tokamak, both from divertor and main chamber. In particular, a poloidal limiter protecting an ion cyclotron resonance heating (ICRH) antenna is used as proxy for chamber sourcing. The key carried out by stepping up lower hybrid current drive (LHCD) power, only auxiliary power source. Limiter W sources exhibit qualitatively similar...
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...
Abstract The HL-2M tokamak is a new medium-sized at SouthWestern Institute of Physics. Two its key missions are to achieve 10 keV ion temperature and investigate the behavior energetic particles relevant burning plasmas. A 6 MW cyclotron range frequencies (ICRF) heating power embedded in next upgrade program HL-2M. In order facilitate engineering design ICRF system, this paper analyses main schemes for HL-2M, terms generation particular. D(H) minority 2nd harmonic D will act as schemes,...
Abstract Two new ICRF antennas operating in the ion cyclotron radio frequency (ICRF) range have been developed for EAST to overcome low coupling problem of original antennas. The were limited their power capacity due insufficient coupling. antenna design takes into account both wave and absorption processes through comprehensive codes, with dominant parallel number 7.5 m −1 at dipole phasing. Through use these antennas, we are able achieve 3.8 MW output 360 s operation, respectively. initial...
Abstract Radiofrequency sheath rectification is a phenomenon relevant to the operation of Ion Cyclotron Range Frequencies (ICRFs) actuators in tokamaks. Techniques model on 3D ICRF antenna geometries have only recently become available (Shiraiw et al 2023 Nucl. Fusion 63 026024; Beers 2021 Phys. Plasmas 28 093503). In this work, we apply ‘sheath-equivalent dielectric layer’ technique, used previously linear devices (Beers 103508), tokamak geometry, computing rectified potentials WEST...
In view of improving ion cyclotron range frequencies (ICRF) wave coupling in EAST (experimental advanced superconducting tokamak) necessary to obtain high-power discharges, two series experiments L-mode were devoted the use local gas injection as a tool increase density front antennas. During first session, quantity deuterium simultaneously puffed from five different poloidal positions on each side one ICRF antenna was gradually increased. Steady puffing this (~8.1020 e s−1) increased...
In this paper, we construct a numerical technique capable of solving Maxwell's equations in the frequency domain, both vacuum and cold magnetized plasma, with boundary condition that guarantees existence potential associated radio electric fields tangential to certain surfaces. This is interest nonlinear sheath physics, since it enables calculation time-dependent current excited by single-frequency electromagnetic wave thereby DC potential.
ou non, émanant des établissements d'enseignement et de recherche français étrangers, laboratoires publics privés.
This study compares experimental observations on plasma surface interactions and heat loads induced by Ion Cyclotron Resonance Heating (ICRH) in WEST medium size tokamak. When powering ICRH, core contamination metallic impurities systematically results an increase of the power radiated, often hardening achievement long discharges H-mode at high power. The radiofrequency (RF) sheaths are excited mainly proximity ICRF antennas, resulting impurity sources. In presence RF sheaths, we show that...
Plasma heating in the full tungsten (W) environment a steady-state tokamak (WEST) relies on electromagnetic waves both lower hybrid (LH) and ion cyclotron range of frequencies (ICRF). The present study focuses mostly optimization discharges heated with ICRF, by reporting different methods to first optimize wave coupling, their absorption reduce impurity production. It is shown that ICRF coupling can be optimized moving plasma closer antennas, increasing density, frequency LH power. We show...
High-Z impurities production is often observed during Ion Cyclotron Range of Frequencies (ICRF) waves' injection, which are likely due to RF sheath formation on solid materials. Based Extreme UV (EUV) spectrometry data, this study in EAST consists extracting information plasma-surface interactions ICRH. Intensities the different spectral lines normalized line-integrated plasma density, exhibit parametric dependencies over scans ICRH and LH power for toroidal phasing between straps. Materials...
Waves in the Ion Cyclotron Range of Frequencies (ICRF) enhance local Plasma-Surface Interactions (PSI) near wave launchers and magnetically-connected objects via Radio-Frequency (RF) sheath rectification. ITER will use 20MW ICRF power over long pulses, questioning long-term impact RF-enhanced localized erosion on lifetime its Beryllium (Be) wall. Recent dedicated ICRF-heated L-mode discharges documented this process JET for different types antennas. Using visible spectroscopy discharges,...
The paper discusses the characterization of three high power steady-state and load-resilient ICRF launchers WEST before their installation in tokamak. These have been characterized validated low-power experiments (milliwatt range) as well at nominal RF voltages currents TITAN vacuum chamber (∼30 kV 915 A peak). successful commissioning two during C3 campaign ∼1 MW level is illustrated. Manual real-time controlled impedance-matching are discussed, validation load-resilience. Furthermore,...
Waves in the Ion Cyclotron (ICRF) and Lower Hybrid (LH) Range of Frequencies are efficient techniques respectively to heat plasma drive current. Main difficulties come from a trade-off between good RF coupling acceptable level impurities release. The mutual influence both systems makes such equilibrium often hard reach [1]. In order investigate those interactions based on Scrape-Off Layer (SOL) parameters, new reciprocating probe was designed allying three tips Langmuir with an emissive...
In this paper we discuss recent improvements to the ICRF antenna coupling code "RAdiofrequency wave couPLing for Ion Cyclotron Antenna in Scrape-Off-Layer" or RAPLICASOL short, including its ability handle curved geometries, simulate propagation through plasmas with arbitrary 3D density and magnetic field profiles, validation against other codes such as TOPICA ERMES.