P. Dumortier
A5062297273- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Electromagnetic Simulation and Numerical Methods
- Gyrotron and Vacuum Electronics Research
- Antenna Design and Analysis
- Electromagnetic Scattering and Analysis
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Geophysical Methods and Applications
- Solar and Space Plasma Dynamics
- Electrostatic Discharge in Electronics
- Atomic and Molecular Physics
- Energy Harvesting in Wireless Networks
- Electromagnetic Launch and Propulsion Technology
- Meteorological Phenomena and Simulations
- Advanced Antenna and Metasurface Technologies
- Microwave Engineering and Waveguides
- Nuclear Materials and Properties
- Laser-induced spectroscopy and plasma
- High-Energy Particle Collisions Research
Royal Military Academy
2013-2024
Culham Centre for Fusion Energy
2017-2023
Culham Science Centre
2016-2023
United Kingdom Atomic Energy Authority
2020-2021
European Steel Association
2017-2020
Laboratoire de Physique des Plasmas
1992-2015
École Spéciale Militaire de Saint-Cyr
2015
ITER
2009-2013
Belgian Development Agency
2013
Ghent University Hospital
2012
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....
Abstract After the second Deuterium–Tritium Campaign (DTE2) in JET tokamak with ITER-Like Wall (ILW) and full tritium campaigns that preceded followed after DTE2, a sequence of fuel recovery methods was applied to promote removal from wall components. The started several days baking main chamber walls at 240 °C 320 °C. Subsequently, superimposed Ion-Cyclotron Conditioning (ICWC) Glow Discharge (GDC) cleaning cycles deuterium. Diverted plasma operation deuterium different strike point...
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...
Impurity injection in the JET ELMy H-mode regime has produced high-confinement, quasi-steady-state plasmas with densities close to Greenwald density. However, at large Ar densities, a sudden loss of confinement is observed. A possible correlation between and observed MHD phenomena, both core edge plasma, was considered. The degradation coincided impurity profile peaking following disappearance sawtooth activity. In addition, density analysis confirmed that central modes prevented peaking....
The main objective of this paper is investigation methods for reduction divertor heat loads in order to increase the lifetime tiles future fusion reactors.Special emphasis given studies transient due edge localized modes (ELMs).Two are compared: argon seeded type-I ELMy H-modes and nitrogen type-III H-modes.In both scenarios, impurity seeding leads a pedestal energy hence released by ELM.This consequentially reduces power load targets.At high radiative fractions H-modes, part that ELM (small...
The performance on plasma of the antennas proposed ITER ICRF system is evaluated by means antenna 24 × impedance matrix provided TOPICA code and confirmed interpreted semi-analytical ANTITER II (summarized in an appendix). From this analysis following characteristics can be derived: (1) a roughly constant power capability entire 40–55 MHz frequency band with same maximum voltage eight feeding lines obtained for all considered heating current drive phasings account broadbanding effect service...
Dedicated experiments have been carried out at the TEXTOR tokamak in biasing-induced improved confinement regimes using Langmuir probe and GPI measurements. The results show first evidence for intimate interaction among sheared flows, eddy structures, Reynolds stress, zonal ambient fluctuations during a transition to an confinement. flows impose dynamic effects on turbulence resulting generation of stress eventually suppression background fluctuation levels via nonlinear energy transfer...
Dedicated experiments to generate energetic D ions and fusion-born alpha particles were performed at the Joint European Torus (JET) with ITER-like wall (ILW). Using 3-ion radio frequency (RF) heating scenario, deuterium from neutral beam injection (NBI) accelerated in core of mixed plasmas higher energies ion cyclotron resonance (ICRF) waves, turn leading a core-localized source particles. The fast-ion distribution RF-accelerated D-NBI was controlled by varying ICRF NBI power ( 4–6 MW, 3–20...
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
Abstract The reference ion cyclotron resonance frequency (ICRF) heating schemes for ITER deuterium–tritium (D-T) plasmas at the full magnetic field of 5.3 T are second harmonic and 3 He minority heating. wave-particle location these coincide central a wave 53 MHz T. Experiments have been carried out in major D-T campaign (DTE2) JET, its prior D campaigns, to integrate ICRF scenarios JET high-performance compare their performance with commonly used hydrogen (H) In 50:50 D:T plasmas, up 35% 5%...
An overview is given of the experimental method, analysis technique and results for trace tritium experiments conducted on JET tokamak in 2003. Observations associated with events such as sawtooth collapses, neo-classical tearing modes edge localized are described. Tritium transport seen to approach levels plasma core at high density low q(95), barrier region internal (ITB) discharges. remains well above all other cases. The correlation measured diffusion coefficient convection velocity...
Recent achievements in studies of the effects ICRF (Ion Cyclotron Range Frequencies) power on SOL (Scrape-Off Layer) and PWI (Plasma Wall Interactions) ASDEX Upgrade (AUG), Alcator C-Mod, JET-ILW are reviewed. Capabilities to diagnose model effect DC biasing associated impurity production at active antennas magnetic field connections described. The experiments show that near-fields can lead not only E × B convection, but also modifications density, which for C-Mod limited a narrow region...
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...
The recent development of real-time measurements and control tools in JET has enhanced the reliability reproducibility relevant ITER scenarios. Diagnostics such as charge exchange, interfero-polarimetry, electron cyclotron emission have been upgraded for measurements. In addition, processes like magnetic equilibrium q profile reconstruction developed applied successfully experiments using model based techniques. Plasma operation against magnetohydrodynamic instabilities are also benefiting...
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)...
Beam-target reactions are responsible for a substantial fraction of the fusion power generated in D-T plasmas JET-ILW (Be/W-wall), with ion temperatures 10-12keV and large neutral-beam injection (NBI) power.It is known that injecting D beam ions energies ~100-150keV T-rich has larger potential beam-target than 50:50 D:T plasmas, but such scenario was never developed past experiments performed JET-C (Carbon-wall) TFTR 90's.On top intrinsic advantages using beams neutron production,...
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)...
This paper addresses the issues of impurity behaviour during argon seeding experiments in JET, which and D2 have been simultaneously puffed ELMy H-mode discharges to reach high density regimes, maintaining good confinement properties throughout plasma discharge. The analysis is based mainly on a 1-D diffusion model, evaluates transport coefficients three experimental scenarios.
Recent progress towards obtaining high density and confinement in JET as required for the ITER reference scenario at Q = 10 is summarized. Plasmas with simultaneous H98(y,2) 1 densities up to n/nGW~1 are now routinely obtained. This has been possible (i) by using plasmas (δ~0.5) medium (δ~0.3-0.4) triangularity sufficient heating power maintain Type I ELMs, (ii) impurity seeded low (δ⩽0.2) triangularity, (iii) an optimized pellet injection sequence, maintaining energy raising density, (iv)...