F. Durodié
A5045593524- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Gyrotron and Vacuum Electronics Research
- Laser-Plasma Interactions and Diagnostics
- Antenna Design and Analysis
- Nuclear reactor physics and engineering
- Electromagnetic Simulation and Numerical Methods
- Electromagnetic Scattering and Analysis
- Geophysical Methods and Applications
- Atomic and Molecular Physics
- Electromagnetic Launch and Propulsion Technology
- Energy Harvesting in Wireless Networks
- Electrostatic Discharge in Electronics
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Electromagnetic Compatibility and Measurements
- Lightning and Electromagnetic Phenomena
- Microwave Engineering and Waveguides
- Laser Design and Applications
- High-Energy Particle Collisions Research
- Anomaly Detection Techniques and Applications
Culham Science Centre
2009-2024
CEA Cadarache
2013-2024
Culham Centre for Fusion Energy
2017-2024
Royal Military Academy
2012-2023
Leefmilieu Brussel
2023
Max Planck Society
2018
Max Planck Institute for Plasma Physics
2018
European Steel Association
2017
Forschungszentrum Jülich
1986-2016
École Normale Supérieure - PSL
1986-2015
Abstract The optimized superconducting stellarator device Wendelstein 7-X (with major radius , minor and plasma volume) restarted operation after the assembly of a graphite heat shield 10 inertially cooled island divertor modules. This paper reports on results from first high-performance operation. Glow discharge conditioning ECRH discharges in helium turned out to be important for density edge radiation control. Plasma densities with central electron temperatures were routinely achieved...
Edge radial electric fields were induced in the edge of TEXTOR tokamak by means a polarization electrode order to study their influence on plasma profiles and its confinement. The studies include generation H-mode behaviour with either positive or negative polarity. Particle confinement (τp) deuterium impurity ions as well energy (τE) are investigated. For which remain below threshold for L-H transition, an interesting regime reduced particle without noticeable loss is found. A strong...
Abstract Fusion energy research has in the past 40 years focused primarily on tokamak concept, but recent advances plasma theory and computational power have led to renewed interest stellarators. The largest most sophisticated stellarator world, Wendelstein 7-X (W7-X), just started operation, with aim show that earlier weaknesses of this concept been addressed successfully, intrinsic advantages persist, also at parameters approaching those a future fusion plant. Here we first physics...
The next step in the Wendelstein stellarator line is large superconducting device 7-X, currently under construction Greifswald, Germany. Steady-state operation an intrinsic feature of stellarators, and one key element 7-X mission to demonstrate steady-state plasma conditions relevant for a fusion power plant. device, on hand, requires implementation special technologies, giving rise technical challenges during design, fabrication assembly such device. On other also physics development at...
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
Stationary high energy confinement is observed on TEXTOR-94 for times limited only by the flux swing of transformer using strong edge radiation cooling. Necessary tools are feedback control radiated power and plasma content. At highest densities obtained (up to 1.2 Greenwald limit), exceeds edge-localized-mode-free H-mode scaling ITERH93-P more than 20%. β limits reached with fH89/qa≈0.6. No detrimental effect seeded impurity seen. These discharges meet many conditions necessary a fusion...
In JET, lower hybrid (LH) and ion cyclotron resonance frequency (ICRF) wave absorption in the scrape-off layer can lead to enhanced heat fluxes on some plasma facing components (PFCs). Experiments have been carried out characterize these loads order to: (i) prepare JET operation with Be wall which has a reduced power handling capability as compared carbon (ii) better understand physics driving phenomena propose solutions for next generation systems reduce them. When using ICRF, hot spots are...
This paper summarizes the operational experience of ion cyclotron resonant frequency (ICRF) ITER-like antenna on JET aiming at substantially increasing power density in range requirements for ITER combined with load resiliency. An in-depth description its commissioning, aspects and achieved performances is presented.
The radiative improved (RI) mode is a tokamak regime offering many attractive reactor features. In the article, RI of TEXTOR-94 shown to follow same scaling as linear ohmic confinement and thus identified one most fundamental operational regimes. current understanding derived from experiments modelling conditions necessary for sustaining reviewed, are mechanisms leading L-RI transition. article discusses compatibility high impurity seeding with low central power density burning reactor, well...
Improved confinement is achieved on TEXTOR under high power conditions (up to 4 MW of additional heating with NBI-co+ICRH, NBI-co+counter or NBI-co+counter+ICRH) edge radiative cooling employing silicon neon as the radiating impurities. It shown that in quasi-stationary up 85% input can be radiated. Such fractions offer possibility utilizing these techniques facilitate exhaust problem for a Tokamak reactor. Discharges exhibit enhanced properties at densities, e.g. central line averaged...
The reference design for the ICRF antenna of ITER is constituted by a tight array 24 straps grouped in eight triplets. matching network must be load resilient operation ELMy discharges and have spectrum control heating or current drive operation. resilience based on use either hybrid couplers conjugate-T circuits. However, mutual coupling between triplets at low expected loading strongly counteracts control. Using mock-up with adjustable water solutions are designed. These derived from...
The current status of the mechanical and electromagnetic design for ICRF antenna system W7-X is presented. Two plugins are discussed: one consisting a pair straps with pre-matching to cover first frequency band, 25–38 MHz, second two short strap triplets band around 76 MHz. This paper focusses on lower band. Power coupling reference plasma profile studied help codes TOPICA Microwave Studio that deliver scattering matrix needed optimization geometric parameters box. Radiation power spectra...
An overview of the results obtained so far for radiative I-mode regime on upgraded Torus Experiment Technology Oriented Research (TEXTOR-94) [Proceedings 16th IEEE Symposium Fusion Engineering (Institute Electrical and Electronics Engineers, Piscataway, NJ, 1995), Vol. 1, p. 470] is given. This under quasistationary conditions with edge neon seeding in a pumped limiter tokamak circular cross section. It combines high confinement β (up to normalized beta, βn=2) low q values (down qa=2.8)...
Additional heating systems can be a source of impurities in fusion plasmas. Studying the behaviour such is important to understand and minimize their effects on tokamak plasma performance. In this paper we present detailed study influence ion cyclotron resonance (ICRH) impurity content JET Using spectroscopic methods monitor Ni release by two ICRH antenna types JET: so-called ITER-like A2 antennas. The during presented as function power density, total applied, relative phasing straps, D2 gas...
An overview is presented of recent experiments with radiating mantles on limiter and divertor machines, realizing simultaneously high confinement density at high-radiation levels. A variety operational regimes has been observed the characteristics each are documented. High-performance plasmas (i.e. edge localized mode (ELM)-free H-mode quality normalized beta values simultaneously) have demonstrated under quasistationary conditions during maximum flattop time machine (equal to tens times)...
ITER as a superconducting fusion machine needs efficient wall conditioning techniques for application in the presence of permanent high toroidal magnetic field (i) reducing in-vessel impurity content, (ii) controlling surface hydrogen isotopic ratio and (iii) mitigating long-term tritium inventory build-up. Encouraging results recently obtained with ion-cyclotron (ICWC) present-day tokamaks stellarators have raised ICWC to status one most promising available routine inter-pulse overnight...
The paper summarizes the continuous developments made to ion cyclotron resonant frequency (ICRF) system at JET in order improve reliability of power coupled plasma. It details changes and improvements so that more is during ELMy plasmas as well increasing density demonstrate reliable operation range requirements for ITER. Results obtained using conventional matching (stubs trombones) system, 3 dB couplers conjugate-T scheme with variable elements outside wave launching structure (external...
A novel technique for sawteeth control in tokamak plasmas using ion-cyclotron resonance heating (ICRH) has been developed the JET-ILW tokamak.Unlike previous ICRH methods, that explored destabilization of internal kink mode when radio-frequency (RF) wave absorption was placed near q=1 surface, presented here consists stabilizing as fast possible by applying power centrally and subsequently induce a sawtooth crash switching it off at appropriate instant.The validation this method L-mode...
A load-tolerant External Conjugate-T (ECT) impedance matching system for two A2 Ion Cyclotron Resonance Heating (ICRH) antennas has been successfully put into operation at JET.The allows continuous injection of the RF power plasma in presence strong antenna loading perturbations caused by Edge Localized Modes (ELMs).Reliable ECT performance demonstrated under a variety conditions including H-mode plasmas with Radial Outer Gaps (ROG) range 4-14 cm.The high resilience to ELMs predicted during...
Four new low field side antennae grouped in pairs have been installed on TEXTOR. It is found that the interaction with wall (density rise, impurity generation) significantly reduced when operating each pair out of phase ( pi ) as opposed to (0). The beneficial effect configuration obtained without drop plasma loading. This experimental property shown, from theory, be explained by judicious choice geometrical configuration. A further improvement made possible an appropriate conditioning (wall...