A5017392064- 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
- Plasma Diagnostics and Applications
- Nuclear Engineering Thermal-Hydraulics
- Network Security and Intrusion Detection
- Nuclear reactor physics and engineering
- GNSS positioning and interference
- Electron and X-Ray Spectroscopy Techniques
- Nuclear Materials and Properties
- Genetics, Aging, and Longevity in Model Organisms
- Particle Accelerators and Free-Electron Lasers
- earthquake and tectonic studies
- Semiconductor materials and devices
- Geophysical Methods and Applications
- Heat transfer and supercritical fluids
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- Atomic and Molecular Physics
Max Planck Institute for Plasma Physics
2016-2025
ITER
2024
Max Planck Society
2015-2021
Technical University of Munich
2017
Abstract The optimized superconducting stellarator device Wendelstein 7-X (with major radius , minor and plasma volume) restarted operation after the assembly of a graphite heat shield 10 inertially cooled island divertor modules. This paper reports on results from first high-performance operation. Glow discharge conditioning ECRH discharges in helium turned out to be important for density edge radiation control. Plasma densities with central electron temperatures were routinely achieved...
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 Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on ASDEX-Upgrade tokamak, as demonstrated experimentally. mechanism of excitation and nonlinear evolution is not yet fully understood. In present work, a first-principles simulation using MEGA code investigated properties in both linear growth saturated phases. Here we show that successfully reproduced coexistence these two modes, agreed with experimental results well. Conclusive evidence showed...
Abstract On the basis of several recent breakthroughs in fusion research, many activities have been launched around world to develop power plants on fastest possible time scale. In this context, high-fidelity simulations plasma behavior large supercomputers provide one main pathways accelerating progress by guiding crucial design decisions. When it comes determining energy confinement a magnetic device, which is key quantity interest, gyrokinetic turbulence are considered approach choice –...
The most recent experiments of disruption mitigation by massive gas injection in ASDEX Upgrade have concentrated on small-relatively to the past-quantities noble injected, and search for minimum amount necessary thermal loads divertor a significant reduction vertical force during current quench. A scenario generation long-lived runaway electron beam has been established; this allows study dissipation moderate quantities argon injected. This paper presents these results discusses them more...
Abstract The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance physics base of ITER and DEMO. Here, full tungsten wall is a key asset for extrapolating future devices. high overall heating power, flexible mix comprehensive diagnostic set allows studies ranging from mimicking scrape-off-layer divertor conditions DEMO at density fully non-inductive operation ( q 95 = 5.5, ) low density. Higher installed electron cyclotron...
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 A series of ice pellets was injected into the advanced stellarator Wendelstein 7-X (W7-X). Although were small and slow, deep efficient particle fueling could be observed experimentally. The most striking feature appearing after injection pellets, however, a transient increase in energy confinement time. This phase resembled several aspects modes enhanced gas-puff or pellet injection, as other fusion experiments. All experimental attempts, to prolong this phase, failed. In paper,...
Abstract Studies have been performed on the release mechanism for large pellets using high pressure gas in a shattered pellet injector. Typically, are dislodged from cryogenic surface and accelerated down barrel delivered by fast-acting propellant valve. The impact an angled which shatters into many small fragments before entering plasma. This technique was initially demonstrated DIII-D (Commaux et al 2016 Nucl. Fusion 56 046007) is now deployed JET, KSTAR, ASDEX-Upgrade, other tokamaks...
Abstract In tokamaks, a leading platform for fusion energy, periodic filamentary plasma eruptions known as edge-localized modes occur in plasmas with high-energy confinement and steep pressure profiles at the edge. These could damage tokamak wall but can be suppressed using small three-dimensional magnetic perturbations. Here we demonstrate that these perturbations change topology just inside gradient region of We identify signatures island, their observation is linked to suppression modes....
The JT-60SA tokamak, being built under the Broader Approach agreement jointly by Europe and Japan, is due to start operation in 2020 expected give substantial contributions both ITER DEMO scenario optimisation. A broad set of preparation activities for an efficient experiments on carried out, involving elaboration Research Plan, advanced modelling various domains, feasibility conception studies diagnostics other sub-systems connection with priorities scientific programme, development...
JT-60SA, the largest tokamak that will operate before ITER, has been designed and built jointly by Japan Europe, is due to start operation in 2020.Its main missions are support ITER exploitation contribute demonstration fusion reactor machine scenario design.Peculiar properties of JT-60SA its capability produce long-pulse, high-β, highly shaped plasmas.The preparation Research Plan, plasma scenarios, producing physics results not only relevant future experiments, but often constitute...
The paper describes under which plasma and machine conditions runaway electrons (REs) are generated during ASDEX Upgrade disruptions. REs created by argon injection to investigate methods of current energy dissipation. RE beams stable last up a few hundred milliseconds. experimental findings described made available for the validation theoretical models. In following, simple 0D fluid model is used simulate observed magnitude time behavior. spite its simplicity, consistent with measured...
Abstract A large superconducting machine, JT-60SA has been constructed to provide major contributions the ITER program and DEMO design. For success of project fusion reactor, understanding development plasma controllability in relevant higher beta regimes are essential. focused on for scenario risk mitigation as well investigating regimes. This paper summarizes high research priorities strategy project. Recent works simulation studies prepare physics control experiments presented, such...
A new high speed gas valve was developed for disruption mitigation studies in the tokamak ASDEX Upgrade. The designed to operate inside vacuum vessel reduce time of flight injected and prevent dispersion cloud before reaches plasma. spring-driven mechanism chosen as it is robust against magnetic fields electromagnetic disturbances vessel. internal reservoir (128 cm3) valve, which holds gas, opened within 1.5 ms, maximal stroke between plate nozzle (diameter 13 mm) 4.5 mm. This allows a peak...
Disruption mitigation remains a critical and unresolved issue for ITER.Measurement uncertainties preventing quantification of system's efficacy significant hurdle in producing validating viable disruption system.This study addresses this through the creation dataset on ASDEX Upgrade tokamak targeted at developing analysis techniques to quantify that are applicable irrespective system being studied.These experiments used range thermal energy fractions address concerns ITER from JET massive...
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...
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...