A5026634979- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Gas Dynamics and Kinetic Theory
- Radiative Heat Transfer Studies
- Metallurgical Processes and Thermodynamics
- High-pressure geophysics and materials
- Ion-surface interactions and analysis
- Advanced Control Systems Optimization
- X-ray Spectroscopy and Fluorescence Analysis
- Electron and X-Ray Spectroscopy Techniques
- Advanced Sensor Technologies Research
- Geophysical and Geoelectrical Methods
- Advanced Data Storage Technologies
Max Planck Institute for Plasma Physics
2016-2025
Institut de Recherche sur la Fusion par Confinement Magnétique
2024
CEA Cadarache
2024
Culham Science Centre
2024
Culham Centre for Fusion Energy
2024
Max Planck Society
2012-2021
National Centre for Nuclear Research
2021
Max Planck Institute for Plasma Physics - Greifswald
2016
Institute for Particle and Nuclear Physics
2016
HUN-REN Wigner Research Centre for Physics
2016
First experiments with nonaxisymmetric magnetic perturbations, toroidal mode number $n=2$, produced by newly installed in-vessel saddle coils in the ASDEX Upgrade tokamak show significant reduction of plasma energy loss and peak divertor power load associated type-I edge localized modes (ELMs) high-confinement plasmas. ELM mitigation is observed above an density threshold obtained both perturbations that are resonant not safety factor profile. Compared unperturbed ELMy reference plasmas,...
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 understanding of divertor physics and the evolution detachment is crucial for developing capability to model power exhaust in current experiments reliably predict it future fusion devices. In simulations ASDEX Upgrade, an experimentally observed region high density field side scrape-off layer has been recovered. Validated modeling with SOLPS5.0 shows that a detailed match plasma not only important local parameters, but can lead strong changes global parameters. Drifts play role...
Abstract Based on particle and energy balances, a reduced model is derived for the physical mechanisms leading to occurrence of stable unstable X-point radiators (XPRs), latter also known as marfes. The roles neutral deuterium density in divertor region initiating XPRs highlighted. An access condition formulated whose parameter dependencies are consistent with experimental observations which could apply process detachment. With an exponential increase recombination rate at low temperature,...
This paper compares the essential divertor transport features of poloidal divertor, which is well developed for tokamaks, and non-axisymmetric divertors currently investigated on helical devices. It aims at surveying fundamental similarities differences in concept geometry, their consequences functioning a divertor. In particular, importance various terms governing axisymmetric scrape-off layers (SOLs) examined, with special attention being paid to energy, momentum impurity transport....
A summary of recent results on filamentary transport, mostly obtained with the ASDEX-Upgrade tokamak (AUG), is presented and discussed in an attempt to produce a coherent picture scrape-off layer (SOL) transport. clear correlation found between L-mode density shoulder formation outer midplane transition sheath-limited inertial regimes. Divertor collisionality be parameter triggering transition. reduction ion temperature takes place far SOL after transition, both for background filaments....
Plasma exhaust has been identified as a major challenge towards the realisation of magnetic confinement fusion. To mitigate risk that single null divertor (SND) with high radiation fraction in scrape-of-layer (SOL) adopted for ITER will not extrapolate to DEMO reactor, EUROfusion consortium is assessing potential benefits and engineering challenges alternative configurations. Alternative configurations could be readily design include X (XD), Super-X (SXD), Snowflake (SFD) double (DND). The...
Future fusion reactors require a safe, steady-state divertor operation. With deep detachment, which is typically induced by impurity seeding, the radiation concentrates in small region at X-point or on closed flux surfaces above X-point. This so-called radiator (XPR) moves further inside confined with increasing seeding and location can be actively controlled. At AUG, parameter space for operation an XPR was significantly extended, using active feedback location. The observed nearly whole...
We present a novel concept to tackle the power exhaust challenge of magnetically confined fusion plasma. It relies on prior establishment an X-point radiator that dissipates large fraction before it reaches divertor targets. Despite spatial proximity magnetic X point confinement region, this singularity is far away from hot plasma in coordinates and therefore allows coexistence cold dense with high potential radiate. In compact radiative (CRD) target plates are placed close point. here...
Experiments on ASDEX Upgrade and other tokamaks have shown that the magnitude of mechanical forces thermal loads during disruptions can be significantly reduced by raising plasma density with massive injection noble gases. This method should applicable to ITER too. Nevertheless, suppression runaway electron (RE) avalanche requires a much larger (two order magnitude) rise. paper reports recent experiments aimed at increasing towards critical value, needed for collisional REs. An effective...
Electron cyclotron resonance heating (ECRH)-assisted plasma breakdown is foreseen with full and half magnetic field in ITER. As reported earlier, the corresponding O1- X2-schemes have been successfully used to assist pre-ionization present-day devices. This contribution reports on common experiments studying effect of toroidal inclination ECR beam, which ⩾20° All devices could demonstrate successful assistance for this case also, although some necessary power was almost a factor 2 higher...
TCV experiments demonstrate the basic power exhaust properties of snowflake (SF) plus and SF minus divertor configurations by measuring heat fluxes at each their four legs. The measurements indicate an enhanced transport into private flux region a reduction peak compared to similar single null configuration. There are indications that this cannot be explained modified field line geometry alone likely requires additional or cross-field channel. measurements, however, do not show broadening...
Blob properties are studied in the scrape-off layer of tokamak ASDEX Upgrade with a fast camera. The gas-puff imaging technique is used to investigate detection rate as well blob size and velocity scaling. experiments were performed L- H-mode phases same discharges study change after L-H transition. In both regimes order few thousand blobs per second, which compatible picture generation by edge micro instabilities. increases H-mode, while radial decreases slightly. changes are, however, not...
Abstract Results from three-dimensional modeling of plasma edge transport and plasma–wall interactions during application resonant magnetic perturbation (RMP) fields for control edge-localized modes in the ITER standard 15 MA Q = 10 H-mode are presented. The full 3D fluid kinetic neutral code EMC3-EIRENE is used modeling. Four characteristic perturbed topologies considered discussed with reference to axisymmetric case without RMP fields. Two field amplitudes at half ELM coil current...
Abstract The X-point radiator (XPR) is an attractive scenario that may contribute to solving the power exhaust problem in future fusion devices. 2D transport code SOLPS-ITER was applied reproduce experimentally measured plasma condition with XPR ASDEX Upgrade tokamak and compare a reduced model. Neutrals penetrating from adjoining cold divertor region large connection length near play important role initiating XPR. However, once such created, it persists even if fueling impurity seeding...
Abstract The physics governing the height of X-point radiator and influence related radiation losses on edge temperature profiles is studied with a reduced power balance model, which an extension model developed to study access. For ASDEX Upgrade parameters heating 10 MW, reproduces that can be moved from up 14 cm into confined plasma, dissipating 70 % power. key parameter neutral density in region. A reduction kinetic pressure gradient about 50 found could explain suppression localized modes...
The impact of edge localized modes (ELMs) and externally applied resonant non-resonant magnetic perturbations (MPs) on fast-ion confinement/transport have been investigated in the ASDEX Upgrade (AUG), DIII-D KSTAR tokamaks.Two phases with respect to ELM cycle can be clearly distinguished ELM-induced losses.Inter-ELM losses are characterized by a coherent modulation plasma density around separatrix while intra-ELM appear as well-defined bursts.In high collisionality plasmas mitigated ELMs,...
Abstract The EMC3-Eirene code package was applied for the first time to simulate edge plasma in an ASDEX Upgrade discharge, which newly installed magnetic perturbation (MP) coils were used mitigate edge-localized modes (ELMs). Two different points during this discharge simulated, ELM-mitigated phase after turning-on of MP and, as a reference, ELMy H-mode before. results compared with measurements various and divertor diagnostics. Assuming main chamber profiles be shifted by 15 mm respect...
Research towards a plasma exhaust solution for fusion power plant aims at validating edge physics models, strengthening predictive capabilities and improving the divertor configuration. The TCV tokamak is extensively used to investigate extent that geometric configuration modifications can affect performance. Recent experiments continue previous detachment studies of Ohmically heated L-mode plasmas in standard single-null configurations, benefitting from range improved diagnostic...
Plasmas in machines with all metal plasma facing components have a lower Zeff, less radiation cooling the scrape-off layer and divertor regions are prone to impurity accumulation core. Higher gas puff seeding of low-Z impurities applied prevent accumulation, increase frequency edge localised modes cool divertor. A power threshold for transition from low-confinement mode high confinement has been found wall when compared carbon machines. The application lithium before or during discharges can...
A physics and engineering analysis of alternative divertor configurations is carried out by examining benefits problems comparing the baseline single null solution with a Snowflake, an X- Super-X divertor. It observed that can provide margin resilience against large power fluctuations, but their has intrinsic difficulties, especially in balance between structural solidity accessibility components when specific poloidal field coil positioning poses further constraints. hybrid proposed as...
For the first time divertor heat and particle fluxes in high-recycling detached deuterium L- H-mode plasmas with rotating magnetic perturbations (MPs) have been measured systematically ASDEX Upgrade (AUG) tokamak. The capability to rotate MP field AUG enabled us obtain full two-dimensional profiles of from measurements triple Langmuir probes. As it was found that initially non-axisymmetric flux became increasingly axisymmetric. In particular no 'burn-through' lobes observed H-mode....