A5030560526- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Genetics, Aging, and Longevity in Model Organisms
- Geophysical Methods and Applications
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
Max Planck Institute for Plasma Physics
2020-2025
Technical University of Munich
2024
Czech Academy of Sciences, Institute of Plasma Physics
2023
Max Planck Society
2020-2021
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...
In a shattered pellet injection (SPI) system the penetration and assimilation of injected material depends on speed size distribution SPI fragments. ASDEX Upgrade (AUG) was recently equipped with flexible to study effect these parameters disruption mitigation efficiency. this paper we impact different 1.5D INDEX code. Scans fragment sizes, speeds compositions are carried out for single into AUG H-mode plasmas. We use semi-empirical thermal quench (TQ) onset condition trends. For mixed...
In support of the ITER disruption mitigation system (DMS), a highly flexible, triple-barrel shattered pellet injection (SPI) was installed at ASDEX Upgrade and tested in 240 dedicated discharges 2022 experimental campaign. Prior to tokamak experiments, commissioned characterised laboratory environment. this paper we discuss experience gained from 2000 launches on freezing launching process for 4 mm 8 diameter pellets made deuterium, neon their mixtures. Different amounts inside as well...
Abstract Disruptions lead to a rapid loss of thermal and magnetic energy can cause large heat loads, mechanical forces, the excitation beam relativistic runaway electrons. The operation tokamaks at high plasma current requires use mitigation system limit such detrimental effects. Mitigation techniques rely mainly on injection amount impurities radiate majority energies. Heat loads electro-magnetic (EM) forces as well their toroidal asymmetries be greatly reduced by measures. In this paper,...
Alternating radiation phenomena between the inner and outer divertor regions in sub kHz range are investigated tokamak ASDEX Upgrade.While oscillates onset fluctuating state of detachment, conditions where it can maintain high recycling or not.The detachment determines magnitude neutral flux through private region, thus sets at divertor.In return these determine particle content divertor, hence divertor.
ASDEX Upgrade has developed multiple massive gas injection (MGI) scenarios to investigate runaway electron (RE) dynamics. During the current quench of MGI induced disruptions, Alfv\'enic activity is observed in 300-800 kHz range. With help a mode tracing algorithm based on Fourier spectrograms, behaviour was classified for 180 discharges. The modes have been identified as global Alfv\'en eigenmodes using linear gyrokinetic MHD simulations. Changes continuum during are proposed explanation...
Abstract Plasma disruptions pose an intolerable risk to large tokamaks, such as ITER. If a disruption can no longer be avoided, ITER’s last line of defense will the Shattered Pellet Injection. An experimental test bench was created at ASDEX Upgrade inform design decisions for controlling shattering pellets and develop techniques generation fragment distributions necessary optimal mitigation. In effort analyze videos resulting from more than 1000 tests determine impact different settings on...
Abstract ASDEX Upgrade has developed multiple massive gas injection (MGI) scenarios to investigate runaway electron (RE) dynamics. During the current quench of MGI induced disruptions, Alfvénic activity is observed in 300–800 kHz range. With help a mode tracing algorithm based on Fourier spectrograms, behaviour was classified for 180 discharges. The modes have been identified as global Alfvén eigenmodes using linear gyrokinetic MHD simulations. Changes continuum during are proposed...
Abstract Shattered pellet injection (SPI) is a promising method for controlling plasma disruptions in tokamaks. In this study, we present numerical modelling of the fragmentation cryogenic deuterium pellets within context SPI, using peridynamic (PD) theory. A dedicated in-house code has been developed, leveraging meshfree and GPU parallelization. The mechanical properties solid are obtained from available literature, calibrated based on shatter threshold along with remaining mass fraction...
Future large tokamaks will operate at high plasma currents and stored energies. To ensure machine protection in case of a sudden loss confinement (major disruption), fraction the magnetic thermal energy must be radiated to reduce loads. The disruption mitigation system for ITER is based on massive material injection form shattered pellet (SPI). support ITER, versatile SPI was installed tokamak ASDEX Upgrade (AUG). AUG features three independent generation cells guide tubes, each equipped...
Shattered pellet injection (SPI) is selected for the disruption mitigation system in ITER, due to deeper penetration, expected assimilation efficiency and prompt material delivery. This article describes non-linear simulations of SPI ASDEX Upgrade tokamak test different parameters neon-doped deuterium pellets using JOREK code. The are executed as fluid simulations. Additional marker particles used evolve charge state distribution impurities based on OpenADAS atomic data, i.e., no coronal...
Plasma-terminating disruptions represent a critical outstanding issue for reactor-relevant tokamaks. ITER will use shattered pellet injection (SPI) as its disruption mitigation system to reduce heat loads, vessel forces, and suppress the formation of runaway electrons. In this paper we demonstrate that reduced kinetic modelling SPI is capable capturing major experimental trends in ASDEX Upgrade experiments, such dependence radiated energy fraction on neon content, or current quench dynamics....
Shattered Pellet Injection (SPI) is considered as a method to effectively mitigate the effect of severe disruptions in tokamaks. For development SPI technology ITER, Centre for Energy Research, collaboration with H-ion Kft and VTMT Kft, designed, constructed operates Disruption Mitigation System (DMS) Support Laboratory. To simulate pellet acceleration, we developed zero-dimensional model. The model uses parameters material, propellant gas characteristics, dimension barrel fast valve (FV),...