A5084445840- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Nuclear Materials and Properties
- Nuclear Physics and Applications
- Nuclear Engineering Thermal-Hydraulics
- High-Energy Particle Collisions Research
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
- Theoretical and Computational Physics
- Electrostatic Discharge in Electronics
- Dust and Plasma Wave Phenomena
- Geomagnetism and Paleomagnetism Studies
- Plasma and Flow Control in Aerodynamics
- Pulsed Power Technology Applications
ITER
2016-2025
CEA Cadarache
2015-2024
Culham Science Centre
2013-2024
Max Planck Institute for Plasma Physics
2015-2024
Institut de Recherche sur la Fusion par Confinement Magnétique
2024
Culham Centre for Fusion Energy
2010-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2021
Royal Military Academy
2020
Institut Méditerranéen d’Océanologie
2019
Max Planck Society
2016-2017
Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, , plasmas and ITER similar shaped (ISS) plasmas, relevant collisionalities . Significant differences the RMP requirements properties of ELM suppressed found when comparing two triangularities. In ISS current required to suppress ELMs is approximately 25% higher than triangularity plasmas. It also that width q95 window for suppression smaller...
An overview of the present status research toward final design ITER disruption mitigation system (DMS) is given. The DMS based on massive injection impurities, in order to radiate plasma stored energy and mitigate potentially damaging effects disruptions. this will be extremely challenging due many physics engineering constraints such as limitations port access amount species injected impurities. Additionally, questions relevant remain unsolved mechanisms for mixing assimilation impurities...
Of all electrons, runaway electrons have long been recognized in the fusion community as a distinctive population. They now attract special attention part of ITER mission considerations. This review covers basic physics ingredients phenomenon and ongoing efforts (experimental theoretical) aimed at electron (RE) taming next generation tokamaks. We emphasize prevailing themes last 20 years: hot-tail mechanism production, RE interaction with impurity ions, role synchrotron radiation kinetics,...
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.
In this paper the manipulation of power deposition on divertor targets at DIII-D by application resonant magnetic perturbations (RMPs) for suppression large type-I edge localized modes (ELMs) is analysed. We discuss modification ELM characteristics RMP applied. It shown that width pattern in ELMy H-mode depends linearly deposited energy, whereas phase discharge those patterns are controlled externally induced perturbation. was also found heat transport due to small, plasma pedestal electron...
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...
A comparison of the L–H power threshold (Pthr) in JET with all carbon, JET-C, and beryllium/tungsten wall (the ITER-like choice), JET-ILW, has been carried out experiments slow input ramps matched plasma shapes, divertor configuration IP/BT pairs. The low density dependence threshold, namely an increase below a minimum ne,min, which was first observed MkII-GB C subsequently not current MkII-HD geometry, is again JET-ILW. At densities above Pthr reduced by ∼30%, ∼40% when radiation from bulk...
A self-consistent analysis of the relevant physics regarding formation and termination runaway beams during mitigated disruptions by Ar Ne injection is presented for selected ITER scenarios with aim improving our understanding underlying heat loads onto plasma facing components (PFCs) identifying open issues developing accessing disruption mitigation schemes ITER. This carried out means simplified models, but still retaining sufficient details key physical processes, including: (a) expected...
For the first time it is experimentally demonstrated on JET tokamak that a combination of low impurity concentration bulk plasma and large magnetohydrodynamic instabilities able to suppress relativistic electron beams without measurable heat loads onto facing components. Magnetohydrodynamic simulations instability modeling postinstability confirm prompt loss runaways absence regeneration during final current collapse. These surprising findings motivate new approach dissipate runaway...
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...
The generation of runaway electrons in the international fusion experiment ITER disruptions can lead to severe damage at plasma facing components. Massive gas injection might inhibit process, but amount needed affect, e.g., vacuum systems. Alternatively, magnetic perturbations suppress by increasing loss rate. In TEXTOR losses were enhanced application resonant with toroidal mode number n=1 and n=2. are initiated fast about 3x10{21} argon atoms, which leads a reliable electrons. At...
A study of three-dimensional (3D) perturbed magnetic field structures and transport for edge localized mode control experiments with resonant perturbations at DIII-D is presented. We focus on ITER-Similar Shape plasmas ITER relevant electron pedestal collisionalities . This performed in comparison results from TEXTOR-Dynamic Ergodic Divertor circular limiter plasmas. For both the structure analyzed vacuum paradigm—superimposing external RMP unperturbed equilibrium. TEXTOR L-mode this...
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...
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....
Recent results from an ITPA joint experiment to study the onset, growth, and decay of relativistic electrons (REs) indicate that loss mechanisms other than collisional damping may play a dominant role in dynamics RE population, even during quiescent Ip flattop. Understanding physics growth mitigation is motivated by theoretical prediction disruptions full-current (15 MA) ITER discharges could generate up 10 MA REs with 10–20 MeV energies. The MHD group conducting measure detection threshold...
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...
Key plasma physics and real-time control elements needed for robustly stable operation of high fusion power discharges in ITER have been demonstrated recent research worldwide.Recent analysis has identified the current density profile as main drive disruptive instabilities simulating ITER's baseline scenario with low external torque.Ongoing development model-based active magnetohydrodynamic is improving stability multiple scenarios.Significant advances made toward physicsbased prediction...
A multi-device database of disruption characteristics has been developed under the auspices International Tokamak Physics Activity magneto-hydrodynamics topical group. The purpose this ITPA (IDDB) is to find commonalities between and mitigation in a wide variety tokamaks order elucidate physics underlying tokamak disruptions extrapolate toward much larger devices, such as ITER future burning plasma devices. In contrast previous smaller data collation efforts, IDDB aims provide significant...
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...