A5044280486- 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
- Solar and Space Plasma Dynamics
- Nuclear Materials and Properties
- Laser-induced spectroscopy and plasma
- Particle Accelerators and Free-Electron Lasers
- High-Energy Particle Collisions Research
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Particle physics theoretical and experimental studies
- Physics of Superconductivity and Magnetism
- High-pressure geophysics and materials
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
- Reservoir Engineering and Simulation Methods
- Advanced Memory and Neural Computing
- Meteorological Phenomena and Simulations
- Lightning and Electromagnetic Phenomena
- Gas Sensing Nanomaterials and Sensors
Max Planck Institute for Plasma Physics
2016-2025
CEA Cadarache
2024
University of Milano-Bicocca
2022
Culham Science Centre
2013-2022
Fusion (United States)
2022
Fusion Academy
2022
Max Planck Society
2012-2021
Royal Military Academy
2020
Max Planck Innovation
2002-2017
Culham Centre for Fusion Energy
2014-2016
Significant progress has been made in the area of advanced modes operation that are candidates for achieving steady state conditions a fusion reactor. The corresponding parameters, domain operation, scenarios and integration issues discussed this chapter. A review presently developed scenarios, including discussions on operational space, is given. heating current drive recent years, especially off-axis drive, which essential achievement required profile. actuators necessary to produce...
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...
The behaviour of tungsten in the core hybrid scenario plasmas JET with ITER-like wall is analysed and modelled a combination neoclassical gyrokinetic codes. In these discharges, good confinement conditions can be maintained only for first 2?3?s high power phase. Later W accumulation regularly observed, often accompanied by onset magneto-hydrodynamical activity, particular tearing modes (NTMs), both which have detrimental effects on global energy confinement. dynamics process examined, taking...
New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [Phys. Rev. Lett. 102, 175002 (2009)] results from combined effect high rotational shear and low magnetic shear. The observations have important implications for understanding improved confinement advanced tokamak scenarios. Simulations using quasilinear fluid gyrofluid models show features mitigation, while nonlinear gyrokinetic simulations do not....
Abstract The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and preparation operation, as well addressing issues for a future DEMO design. Since 2015, AUG equipped with new pair 3-strap ICRF antennas, which were designed reduction tungsten release during operation. As predicted, factor two on ICRF-induced W plasma content could be achieved by sheath voltage at antenna limiters via compensation image currents central side straps in...
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 An overview of results negative triangularity (NT) studies from the ASDEX Upgrade tokamak (AUG) is given. Moderate values in range δ average ≈ −0.2 have been obtained. Results both unfavorable and favorable magnetic configuration terms high-confinement mode (H-mode) access are presented. In configuration, ion grad B drift points away active x-point, which usually a factor 2 higher power thresholds to enter H-mode. low-confinement (L-mode) operation confirmed at high auxiliary...
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...
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.
ASDEX Upgrade has recently finished its transition towards an all-W divertor tokamak, by the exchange of last remaining graphite tiles to W-coated ones. The plasma start-up was performed without prior boronization. It found that large He content in plasma, resulting from DC glow discharges for conditioning, leads a confinement reduction. After change D inter-shot quickly dropped and, parallel, usual H-Mode with H factors close one achieved. initial conditioning phase, oxygen concentrations...
In both JET and ASDEX Upgrade (AUG) the plasma energy confinement has been affected by presence of a metal wall requirement increased gas-fuelling to avoid tungsten pollution plasma.In with beryllium/tungsten high triangularity baseline H-mode scenario (i.e.similar ITER reference scenario) strongest benefit shaping give good normalised H 98 ~1 at Greenwald density fraction f GW ~0.8 disappeared.In AUG full could be achieved in plasmas, albeit elevated pressure β N >2.The lost respect carbon...
In ASDEX Upgrade the compatibility of improved H-modes with an all-W wall has been demonstrated. Under boronized conditions light impurities and radiated power fraction in divertor were reduced, requiring N seeding to cool plasma. The impurity does not only protect tiles but also considerably improves performance H-mode discharges by up 25%. energy confinement increases H 98 -factors 1.3 thereby exceeds best values carbon-dominated AUG at same density collisionality. This improvement is due...
Recent developments in theory-based modelling of core heavy impurity transport are presented, and shown to be necessary for quantitative description present experiments JET ASDEX Upgrade. The treatment impurities is complicated by their large mass charge, which result a strong response plasma rotation or any small background electrostatic field the plasma, such as that generated anisotropic external heating. These forces lead poloidal asymmetries density, have recently been added numerical...
Abstract New experiments in 2013–2014 have investigated the physics responsible for decrease H-mode pedestal confinement observed initial phase of JET-ILW operation (2012 Experimental Campaigns). The effects plasma triangularity, global beta and neutrals on stability been systematically. pedestals is analysed framework peeling–ballooning model assumptions predictive code EPED. Low D content plasma, achieved either by low 2 gas injection rates or divertor configurations with optimum pumping,...
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...
Abstract Ion cyclotron resonance frequency (ICRF) heating has been an essential component in the development of high power H-mode scenarios Jet European Torus ITER-like wall (JET-ILW). The ICRF performance was improved by enhancing antenna-plasma coupling with dedicated main chamber gas injection, including preliminary minimization RF-induced plasma-wall interactions, while RF where optimized for core impurity screening terms ion position and minority hydrogen concentration. impact on...
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...
Type I ELMy H-mode operation in JET with the ITER-like Be/W wall (JET-ILW) generally occurs at lower pedestal pressures compared to those full carbon (JET-C). The density is similar but temperature where type ELMs occur reduced and below so-called critical I–type III transition reported JET-C experiments. Furthermore, confinement factor H98(y,2) baseline plasmas JET-ILW low power fractions Ploss/Pthr,08 < 2 (where Ploss (Pin − dW/dt), Pthr,08 L–H threshold from Martin et al 2008 (J. Phys....
Abstract As part the DTE2 campaign in JET tokamak, we conducted a parameter scan T and D-T complementing existing pulses H D. For different main ion masses, type-I ELMy H-modes at fixed plasma current magnetic field can have pedestal pressure varying by factor of 4 total changing from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo>...
At the central column of ASDEX Upgrade, an area 5.5 m2 graphite tiles was replaced by tungsten-coated representing about two-thirds total column. No negative influence on plasma performance found, except for internal transport barrier limiter discharges. The tungsten influx ΓW stayed below detection limit only during direct wall contact or reduced clearance in divertor discharges spectroscopic evidence could be found. From these observations a penetration factor order 1% and effective...
Recent experiments at ASDEX Upgrade have achieved advanced scenarios with high βN (>3) and confinement enhancement over ITER98(y, 2) scaling, HH98y2 = 1.1–1.5, in steady state. These discharges been obtained a modified divertor configuration for Upgrade, allowing operation higher triangularity, changed neutral beam injection (NBI) system, more tangential, off-axis deposition. The figure of merit, βNHITER89-P, reaches up to 7.5 several seconds plasmas approaching stationary conditions....
Beyond a certain heating power, measured and predicted distributions of neutral beam injection (NBI) driven currents deviate from each other even in the absence MHD instabilities. The most reasonable explanation is redistribution fast NBI ions on time scale smaller than current time. hypothesis by background turbulence discussed. Direct numerical simulation test particles given field electrostatic indicates that for parameters thermal particle diffusion can indeed be similar. High quality...