A5015285836- 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
- Plasma Diagnostics and Applications
- Nuclear Materials and Properties
- Nuclear Physics and Applications
- Nuclear Engineering Thermal-Hydraulics
- Laser-induced spectroscopy and plasma
- Meteorological Phenomena and Simulations
- Metallurgical Processes and Thermodynamics
- Atomic and Molecular Physics
- Marine and Coastal Research
- High-Energy Particle Collisions Research
- Plasma and Flow Control in Aerodynamics
- Thermal Analysis in Power Transmission
- Computational Fluid Dynamics and Aerodynamics
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Gas Dynamics and Kinetic Theory
- Electron and X-Ray Spectroscopy Techniques
- Fault Detection and Control Systems
ITER
2018-2024
Culham Science Centre
2012-2021
United Kingdom Atomic Energy Authority
2021
Royal Military Academy
2020
Institut Méditerranéen d’Océanologie
2020
Culham Centre for Fusion Energy
2012-2019
Instituto Superior Técnico
2017
Forschungszentrum Jülich
2004-2014
Japan External Trade Organization
2014
CEA Cadarache
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...
Disruption mitigation is mandatory for ITER in order to reduce forces, mitigate heat loads during the thermal quench and avoid runaway electrons (REs). A fast disruption valve has been installed at JET study by massive gas injection. Different species amounts have investigated with respect timescales efficiency. We discuss of halo currents as well sideways forces vertical displacement events, increased energy dissipation through radiation, which could arise asymmetric radiation suppression REs.
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.
Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical single-null shapes, poloidal flux expansion at outer strikepoint varied by a factor of 10 to investigate X-divertor characteristics, and total 70 study properties super-X divertor. The effect an additional X-point near target investigated divertors. Detachment studied these plasmas during Ohmic density ramps with ion B drift away primary X-point. threshold, depth detachment, stability...
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...
A new shattered pellet injection system was designed and built to perform disruption mitigation experiments on ASDEX Upgrade. The can inject pellets with diameters of 1, 2, 4, or 8 mm variable lengths over a range L/D ratios ∼0.5-1.5. By using helium deuterium as propellant gas, the be accelerated speeds between 60 750 m/s. velocity slightly depends mass. is capable preparing three in separate barrels at same time. Once by gas pulse, travel through one parallel flight tubes. Each tube...
Disruptions are a critical issue for ITER because of the high thermal and magnetic energies that released on short timescales, which results in extreme forces heat loads. The choice material plasma-facing components (PFCs) can have significant impact loads arise during disruption. With ITER-like wall (ILW) JET made beryllium main chamber tungsten divertor, finding is low fraction radiation. This has dropped significantly with ILW from 50–100% total energy being dissipated disruptions CFC...
Disruptions are a major operational concern for next generation tokamaks, including ITER.They may generate excessive heat loads on plasma facing components, large electromagnetic forces in the machine structures and several MA of multi-MeV runaway electrons.A more complete understanding processes methods to suppress them is necessary ensure safe reliable operation future tokamaks.Runaway electrons were studied at JET-ILW showing that their dependencies (accelerating electric field, avalanche...
The new full-metal ITER-like wall (ILW) at JET was found to have a profound impact on the physics of disruptions. main difference is significantly lower fraction (by up factor 5) energy radiated during disruption process, yielding higher plasma temperatures after thermal quench and thus longer current times. Thus, larger total conducted resulting in heat loads. Active mitigation by means massive gas injection became necessity avoid beryllium melting already moderate levels magnetic (i.e....
Abstract A series of experiments have been executed at JET to assess the efficacy newly installed shattered pellet injection (SPI) system in mitigating effects disruptions. Issues, important for ITER disruption mitigation system, such as thermal load mitigation, avoidance runaway electron (RE) formation, radiation asymmetries during quench electromagnetic control and RE energy dissipation addressed over a large parameter range. The efficiency has examined various SPI strategies. paper...
The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating m/n=3/1 mode configuration, are presented. deeply penetrating external magnetic field perturbation this configuration increases toroidal plasma rotation. Staying below excitation threshold for m/n=2/1 tearing mode, rotation is always direction current, even if projection rotating opposite direction. observed consistent with a radial electric field, generated by an enhanced electron transport ergodic layers near...
For the new ITER-like wall at JET, two infrared diagnostics (KL9B, KL3B) have been installed. These can operate between 3.5 and 5 μm up to sampling frequencies of ∼20 kHz. KL9B KL3B image horizontal vertical tiles divertor. The divertor are tungsten coated carbon fiber composite except central tile which is bulk consists lamella segments. thermal emission lamellae affects surface temperature measurement therefore KL9A has upgraded achieve a higher spatial resolution (by factor 2). A...
The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite requires active protection to prevent excessive heat loads on plasma facing components (PFC). Analog CCD cameras operating in near infrared wavelength are used measure surface temperature PFCs. Region interest (ROI) analysis performed real time maximum measured each ROI sent vessel thermal map. system started October 2011 has already successfully led a safe landing when hot...
Asymmetrical disruptions may occur during ITER operation and they be accompanied by large sideways forces rotation of the asymmetry. This is particular concern because resonance rotating asymmetry with natural frequencies vacuum vessel (and other in-vessel components) could lead to dynamic amplification forces. A significant fraction non-mitigated JET have toroidally asymmetric currents that flow partially inside plasma surrounding ('wall'). The toroidal asymmetries (otherwise known as...
The electron temperature and density pedestals tend to vary in their relative radial positions, as observed DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) ASDEX Upgrade (Dunne 2017 Plasma Control. Fusion 59 14017). This so-called shift has an impact on the pedestal magnetohydrodynamic (MHD) stability hence height (Osborne 2015 Nucl. 55 063018). present work studies effect of JET ITER-like wall (JET-ILW) baseline low triangularity (δ) unseeded plasmas, similar JET-C discharges. As...
The EDGE2D-EIRENE code is applied for simulation of divertor detachment during matched density ramp experiments in high triangularity, L-mode plasmas both JET-Carbon (JET-C) and JET-ITER-Like Wall (JET-ILW). runs without drifts includes either C or Be as impurity, but not W, assuming that the W targets have been coated with via main chamber migration. simulations reproduce reasonably well observed particle flux raised JET-C JET-ILW can better match experimental in-out target power asymmetry...
Shattered pellet injection (SPI) systems that form cryogenic pellets in a pipe-gun for of material to mitigate disruptions have been fabricated and installed use thermal mitigation runaway electron (RE) dissipation experiments on JET KSTAR. These are support disruption research ITER based an ORNL three-barrel design flexibility size selection variable composition studies. The SPI KSTAR common feature the barrels being collimated into single line enters vacuum vessel. shattered bent stainless...