A5014880788- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Spectroscopy and Laser Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Analytical Chemistry and Sensors
- Neural Networks and Applications
- Model Reduction and Neural Networks
- Calibration and Measurement Techniques
- Advanced MRI Techniques and Applications
- nanoparticles nucleation surface interactions
- Particle physics theoretical and experimental studies
Culham Centre for Fusion Energy
2012-2024
United Kingdom Atomic Energy Authority
2003-2024
Culham Science Centre
2015-2024
Royal Military Academy
2020
ITER
2013
Forschungszentrum Jülich
2004-2013
University of Strathclyde
2004-2013
Queen's University Belfast
2005-2013
Max Planck Society
2013
École Polytechnique Fédérale de Lausanne
2013
JET underwent a transformation from full carbon-dominated tokamak to fully metallic device with beryllium in the main chamber and tungsten divertor. This material combination is foreseen for activated phase of ITER. The ITER-Like Wall (ILW) experiment at shall demonstrate plasma compatibility walls reduction fuel retention. We report on set experiments (Ip = 2.0 MA, Bt 2.0–2.4 T, δ 0.2–0.4) different confinement conditions global gas balance analysis demonstrating strong long-term retention...
This paper reports the impact on confinement and power load of high-shape 2.5 MA ELMy H-mode scenario at JET a change from all carbon plasma-facing components to an metal wall. In preparation this change, systematic studies reduction as result fuelling in combination with nitrogen seeding were carried out JET-C are compared their counterpart metallic An unexpected significant is reported decrease pedestal but partially recovered injection nitrogen.
The impact of carbon and beryllium/tungsten as plasma-facing components on plasma radiation, divertor power particle fluxes, neutral conditions in the divertors has been assessed JET both experimentally by edge fluid code simulations for plasmas low-confinement mode. In high-recycling studies show a 30% reduction total radiation scrape-off (SOL) layer when replacing (JET-C) with beryllium main chamber tungsten (JET-ILW). Correspondingly, at low-field side (LFS) plate two-fold increase...
The original goals of the JET ITER-like wall included study impact an all W divertor on plasma operation (Coenen et al 2013 Nucl. Fusion 53 073043) and fuel retention (Brezinsek 083023). ITER has recently decided to install a full-tungsten (W) from start operations. One key inputs required in support this decision was possibility melting melt splashing during transients. Damage type can lead modifications surface topology which could higher disruption frequency or compromise subsequent...
The erosion of tungsten (W), induced by the bombardment plasma and impurity particles, determines lifetime plasma-facing components as well impacting on performance influx W into confined region. screening divertor transport in largely content core, but source strength itself has a vital impact this process. JET tokamak experiment provides access to large set erosion-determining parameters permits detailed description closest ITER one: (i) effective sputtering yields fluxes function energy...
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...
The W-transport in the core plasma of JET is investigated experimentally by deriving W-concentration profiles from modelling signals soft x-ray cameras. For case pure neutral beam heating W accumulates (r/a < 0.3) approaching W-concentrations 10−3 between sawtooth crashes, which flatten W-profile to a concentration about 3 × 10−5. When central Ion cyclotron resonant additionally applied decays phases that exhibit changed mode activity, while also electron temperature increases and density...
A new technique has been developed to produce plasmas with improved confinement relative the H98,y2 scaling law (ITER Physics Expert Groups on Confinement and Transport Modelling Database ITER Basics Editors EDA 1999 Nucl. Fusion 39 2175) JET tokamak. In mid-size tokamaks ASDEX upgrade DIII-D heating during current formation is used a flat q-profile minimum close 1. On this leads q-profiles similar q but opposite other not an state. By changing method utilizing faster ramp temporary higher...
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...
This paper reports the progress made at JET-ILW on integrating requirements of reference ITER baseline scenario with normalized confinement factor 1, a pressure 1.8 together partially detached divertor whilst maintaining these conditions over many energy times. The 2.5 MA high triangularity ELMy H-modes are studied two different configurations D-gas injection and nitrogen seeding. power load reduction N seeding is reported. relationship between an increase in pedestal investigated....
Abstract Tungsten erosion in H-mode plasmas is quantified the outer divertor of JET ITER-Like Wall environment with optical emission spectroscopy on 400.9 nm atomic neutral tungsten line. A novel cross-calibration procedure developed to link slow, high spectral resolution and fast photomultiplier tube measurements order obtain ELM-resolved photon fluxes. Inter-ELM W exclusively impurity sputtering by beryllium because sputter threshold for deuterons. Low concentrations resulted low inter-ELM...
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...
To consolidate International Thermonuclear Experimental Reactor (ITER) design choices and prepare for its operation, Joint European Torus (JET) has implemented ITER's plasma facing materials, namely, Be the main wall W in divertor. In addition, protection systems, diagnostics, vertical stability control were upgraded heating capability of neutral beams was increased to over 30 MW. First results confirm expected benefits limitations all metal components (PFCs) but also yield understanding...
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 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 This paper reports the first experiment carried out in deuterium–tritium addressing integration of a radiative divertor for heat-load control with good confinement. Neon seeding was time D–T plasma as part second campaign JET its Be/W wall environment. The technical difficulties linked to re-ionisation heat load are reported T and D–T. compares impact neon on plasmas their D counterpart detachment, localisation radiation, scrape-off profiles, pedestal structure, edge localised modes global
Abstract Building on prior analysis of ASDEX Upgrade (AUG) experiments (Henderson et al 2023 Nucl. Fusion 63 086024), this study compares simple analytical formula predictions for divertor detachment onset and reattachment timescales in JET experiments. Detachment primarily scales with neutral pressure, impurity concentration, power directed to the targets, machine size, integral perpendicular decay length. experiments, focusing seeding mixtures Ne Ar, align predictions. Radiation...