J. Mailloux
A5051294610- 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
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Gyrotron and Vacuum Electronics Research
- Solar and Space Plasma Dynamics
- Electrostatic Discharge in Electronics
- Electromagnetic Launch and Propulsion Technology
- Nuclear Materials and Properties
- Physics of Superconductivity and Magnetism
- High-Energy Particle Collisions Research
- Silicon Carbide Semiconductor Technologies
- Meteorological Phenomena and Simulations
- GNSS positioning and interference
- Quantum chaos and dynamical systems
- Advancements in Semiconductor Devices and Circuit Design
- Nuclear Physics and Applications
- Smart Grid Security and Resilience
- Atomic and Molecular Physics
- Advanced Data Storage Technologies
- Geophysical Methods and Applications
Culham Science Centre
2016-2025
United Kingdom Atomic Energy Authority
2003-2024
Culham Centre for Fusion Energy
2011-2024
Royal Military Academy
2020
Sapienza University of Rome
2013
Queen's University Belfast
2005-2013
CEA Cadarache
1999-2012
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1999-2012
Institute of Plasma Physics
2011
Chinese Academy of Sciences
2011
Abstract The JET 2019–2020 scientific and technological programme exploited the results of years concerted engineering work, including ITER-like wall (ILW: Be W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power 2019–2020, tested technical procedural preparation for safe operation with tritium. Research along three complementary axes yielded wealth new results. Firstly, plasma delivered scenarios...
The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like (ILW) has affected plasma energy confinement. To investigate this, experiments have been performed with both C-wall and ILW to vary heating power over wide range for plasmas different shapes.
Abstract In JET deuterium-tritium (D-T) plasmas, the fusion power is produced through thermonuclear reactions and between thermal ions fast particles generated by neutral beam injection (NBI) heating or accelerated electromagnetic wave in ion cyclotron range of frequencies (ICRFs). To complement experiments with 50/50 D/T mixtures maximizing reactivity, a scenario dominant non-thermal reactivity has been developed successfully demonstrated during second campaign DTE2, as it was predicted to...
Abstract The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with ITER-like Be/W wall. development started pure Deuterium refinement of current, and toroidal magnetic field choices succeeded solving heat load challenges arising 37 MW injected power ITER like environment, keeping radiation edge core controlled, avoiding MHD instabilities reaching high neutron rates. have re-run Tritium...
Experiments designed for generating internal transport barriers in the plasmas of Joint European Torus [JET, P. H. Rebut et al., Proceedings 10th International Conference, Plasma Physics and Controlled Nuclear Fusion, London (International Atomic Energy Agency, Vienna, 1985), Vol. I, p. 11] reveal cascades Alfvén perturbations with predominantly upward frequency sweeping. These experiments are characterized by a hollow plasma current profile, created lower hybrid heating drive before main...
Simultaneous current ramping and application of lower hybrid heating drive (LHCD) have produced a region with zero density within measurement errors in the core ( r/a< or =0.2) JET tokamak optimized shear discharges. The reduction is consistent simple physical explanation numerical simulations radial diffusion including effects LHCD. However, clamped at zero, indicating existence mechanism which prevents it from becoming negative.
In the recent JET experimental campaigns with new ITER-like wall (JET-ILW), major progress has been achieved in characterization and operation of H-mode regime metallic environments: (i) plasma breakdown at first attempt X-point L-mode recovered a few days operation; (ii) stationary stable type-I ELMy H-modes βN ∼ 1.4 have low high triangularity shape plasmas are showing that their operational domain H = 1 is significantly reduced JET-ILW mainly because need to inject large amount gas (above...
The JET exploitation plan foresees D–T operations in 2020 (DTE2). With respect to the first campaign 1997 (DTE1), when was equipped with a carbon wall, experiments will be conducted presence of beryllium–tungsten ITER-like wall and benefit from an extended improved set diagnostics higher additional heating power (32 MW neutral beam injection + 8 ion cyclotron resonance heating). There are several challenges presented by new wall: general deterioration pedestal confinement; risk heavy...
The objective of thermonuclear fusion consists producing electricity from the coalescence light nuclei in high temperature plasmas. most promising route to envisages confinement such plasmas with magnetic fields, whose studied configuration is tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one main potential showstoppers on a commercial reactor. In this work we report how, deploying innovative analysis methods thousands JET experiments covering isotopic...
Real-time simultaneous control of several radially distributed magnetic and kinetic plasma parameters is being investigated on JET, in view developing integrated advanced tokamak scenarios. This paper describes the new model-based profile controller which has been implemented during 2006–2007 experimental campaigns. The aims to use combination heating current drive (H&CD) systems—and optionally poloidal field (PF) system—in an optimal way regulate evolution parameter profiles such as...
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...
Experiments on JET with a carbon-fibre composite wall have explored the reduction of steady-state power load in an ELMy H-mode scenario at high Greenwald fraction ∼0.8, constant and close to L H transition. This paper reports systematic study due effect fuelling combination seeding over wide range pedestal density ((4–8) × 1019 m−3) detailed documentation divertor, main plasma conditions, as well comparative two extrinsic impurity nitrogen neon. It also impact overall behaviour, possible...
Abstract A toroidal Alfvén eigenmode (TAE) has been observed to be driven by alpha particles in a JET deuterium-tritium internal transport barrier plasma. The observation occurred 50 ms after the removal of neutral beam heating (NBI). mode is on magnetics, soft-xray, interferometry and reflectometry measurements. We present detailed stability calculations using similar tool set validated during deuterium only discharges. These strongly support conclusion that TAE, this was destabilized...
The fusion-born alpha particle heating in magnetically confined fusion machines is a high priority subject for studies. self-heating of thermonuclear plasma by particles was observed recent deuterium-tritium (D-T) experiments on the joint European torus. This observation possible conducting so-called "afterglow" where transient yield achieved with neutral beam injection as only external source, and then termination at peak performance. allowed first direct evidence electron plasmas alphas to...
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%...
Abstract The fusion reaction between deuterium and tritium, D ( T,n ) 4 He is the main source of energy in future thermonuclear reactors. Alpha-particles -ions) born with an average 3.5 MeV transferring to thermal plasma during their slowing down, should provide self-sustained D–T burn. adequate confinement α -particles essential efficient heating bulk steady burning a reactor plasma. That why fusion-born -particle studies have been priority task second experiments (DTE2) on Joint European...
Abstract JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET's 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-depth physics understanding control schemes. These were evaluated with mixed D-T fuel, using the only remaining tritium-capable tokamak until its closure 2023. A core-edge-SOL integrated H-mode scenario developed tested D-T, showing...
Optimized shear (OS) experiments in JET can generate an internal transport barrier (ITB) during a high power heating phase early the plasma discharge. A strong link is generally observed between formation of and location integer q magnetic surface within low (s = r/q(dq/dr)) region plasma. However, if q-profile for such modified by applying lower hybrid current drive (LHCD) before main pulse, to provide reduced or negative core, ITBs be formed which does not exhibit any apparent association...
Quasi-steady operation has been achieved at JET in the high-confinement regime with internal transport barriers (ITBs). The ITB maintained up to 11 s. This duration, much larger than energy confinement time, is already approaching a current resistive time. high-performance phase limited only by plant constraints. radial profiles of thermal electron and ion pressures have steep gradients typically mid-plasma radius. A large fraction non-inductive (above 80%) sustained throughout poloidal beta...
Quasistationary operation has been achieved on the Joint European Torus tokamak in internal-transport-barrier (ITB) scenarios, with discharge time limited only by plant constraints. Full current drive was obtained over all high performance phase using lower hybrid drive. For first feedback control total pressure and electron temperature profile implemented using, respectively, neutral beams ion-cyclotron waves. Although impurity accumulation could be a problem steady state ITBs, these...
The fusion performance of JET plasmas can be enhanced by the generation internal transport barriers. influence theq-profile shape in local and global plasma has been investigated cases where core magnetic shear ranges from small positive to large negative. Internal barriers extending radii effective raising plasma. It is found that such tend generated more easily if q-profile contains a region negative shear. formation favoured neutral beam injection compared with ion cyclotron resonance...
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...
Externally launched lower hybrid (LH) waves do not propagate into the plasma core during operations of JET with radial profiles relatively high density even at periphery, approaching condition necessary for ITER. Modelling results indicate that this problem would be caused by parametric instability (PI)-induced LH spectral broadening, which is expected to occur in edge and prevents coupled power penetrating core. However, operation electron temperature diminish PI effect extend current drive...