A5039456115- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Solar and Space Plasma Dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- Spacecraft and Cryogenic Technologies
- Laser-induced spectroscopy and plasma
- Data Visualization and Analytics
- Nuclear Physics and Applications
- Astro and Planetary Science
- Metal and Thin Film Mechanics
- Advanced Sensor Technologies Research
- Earthquake Detection and Analysis
- Electron and X-Ray Spectroscopy Techniques
- Multisensory perception and integration
- Gaussian Processes and Bayesian Inference
- Radio Wave Propagation Studies
- Spaceflight effects on biology
- Machine Learning and ELM
- Inertial Sensor and Navigation
Max Planck Institute for Plasma Physics
2016-2025
Max Planck Society
2013-2024
Linköping University
2021
Westinghouse Electric (United States)
1931
Abstract In 2021 JET exploited its unique capabilities to operate with T and D–T fuel an ITER-like Be/W wall (JET-ILW). This second major campaign (DTE2), after DTE1 in 1997, represented the culmination of a series enhancements—new fusion diagnostics, new injection capabilities, refurbishment plant, increased auxiliary heating, in-vessel calibration 14 MeV neutron yield monitors—as well as significant advances plasma theory modelling community. DTE2 was complemented by sequence isotope...
Abstract The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is high-confinement mode. In this regime, however, periodic relaxations of plasma edge can occur. These edge-localized modes pose a threat to integrity fusion device. Here we reveal strong impact energetic ions on spatio-temporal structure in tokamaks using nonlinear hybrid kinetic–magnetohydrodynamic simulations. A resonant interaction between fast at electromagnetic...
Over previous campaigns, an intense experimental program on advanced tokamak (AT) scenarios, has been carried out at the ASDEX Upgrade with full-tungsten wall. These discharges have executed shortly after boronization of first wall to reduce density and impurity influx. The confinement level such AT was found vary considerably, even when similar, if not identical, engineering parameters were out. This work investigates causes variations. Among all plasma quantities analyzed, quality...
Abstract Advanced tokamak (AT) scenarios applying additional heating during the current ramp (early-heating) usually require many iterations if developed fully empirically. To reduce required experimental time, a model has been in ASTRA framework, capable of doing predictive simulations relevant parameters. As scenario development requires fast and inter-discharge runs, sufficiently short run-time is required. While using simplified transport to achieve this, comparisons data from...
A tokamak equilibrium reconstruction can benefit much from internal measurements of the current distribution. If lacking robust measurements, will be ill posed in plasma core, not allowing for a sensible estimation Such deficiencies compensated by modeling distribution evolution employing diffusion equation between successive equilibria. scheme coupling predictive with an inverse Grad-Shafranov solver minimizing least-squares criterion on measured and modeled data is proposed. The intended...
Abstract Rapid inter-discharge simulation and optimization using the RAPTOR code have allowed development of a reliable reproducible early heating strategy for an advanced tokamak (AT) scenario on ASDEX Upgrade. Solving electron heat current diffusion in with ad-hoc formulas transport cyclotron drive (ECCD) efficiency is found to robustly recover coupled dynamics <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>T</mml:mi> <mml:mrow> <mml:mi...
Abstract Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER EU DEMO. A major objective the AUG programme is to shed light underlying physics confinement, stability, plasma exhaust order allow reliable extrapolation results obtained present day machines these reactor-grade devices. Concerning pedestal physics, mitigation edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found be consistent with reduction linear...
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...
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...
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 –...
Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle role plasma fueling shape for onset small ELM regimes. On both devices, regimes with high confinement are achieved if only two conditions fulfilled at same time. Firstly, density separatrix must be large enough (), leading pressure profile flattening separatrix, which stabilizes type-I ELMs. Secondly, magnetic configuration close double null (DN), reduction shear in...
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...
Recent improvements to the heating and diagnostic systems on ASDEX Upgrade tokamak allow renewed investigations into non-inductive operation scenarios with improved confinement in a full-metal device.Motivated by this, scenario β N ≈ 2.7, q 95 5.3 high current fraction f NI 90% has been developed.The offers good H 98 (y, 2) > 1.1 normalised ion temperature gradients R/L T i 12.Moreover, it is robust against resistive magnetohydrodynamic (MHD) instabilities, but does suffer from ideal MHD...
Recent experiments at ASDEX Upgrade achieve non-inductive operation in full tungsten wall conditions by applying electron cyclotron and neutral beam current drive. These discharges are characterised a well-measured safety factor profile, which does not drop below one, good energy confinement. By reproducing the experimental heat fluxes, nonlinear gyrokinetic simulations suggest that observed strong peaking of ion temperature core is caused stabilising impact significant content, as well...
The hybrid scenario is a candidate for stationary high-fusion gain tokamak operation in ITER and DEMO. To obtain such performance, the energy confinement normalized pressure must be maximized, which requires operating near or above ideal MHD no-wall limits. New experimental findings show how these limits can affect operation. Even if hybrids are mainly limited by tearing modes, proximity to limit leads 3D field amplification that affects plasma profiles, e.g. rotation braking observed ASDEX...
Abstract An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling AUG discharges was established which able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In center, theoretical predictions current redistribution by a dynamo effect were confirmed experimentally. For core transport, stabilizing fast ion distributions turbulent transport shown be important explain isotope and...
Abstract In high- β scenarios with on-axis co-current electron cyclotron current drive, which normally lowers q 0 below unity, the absence of sawteeth suggests involvement an additional redistribution mechanism beyond neoclassical diffusion. This is supported by imaging motional Stark effect diagnostic measurements, indicate that remains consistently around 1. phenomenon observed in presence a 1/1 mode, indicating its potential role redistribution. It shown mode’s ability to modify central...
The confinement fast ions, generated by neutral beam injection (NBI), has been investigated at the ASDEX Upgrade tokamak. In plasmas that exhibit strong sawtooth crashes, a significant sawtooth-induced internal redistribution of mainly passing ions is observed, which in very good agreement with theoretical predictions based on Kadomtsev model. Between fishbone modes are excited which, however, do not cause measurable changes global fast-ion population. During experiments on- and off-axis NBI...
Abstract Within the 9th European Framework programme, since 2021 EUROfusion is operating five tokamaks under auspices of a single Task Force called ‘Tokamak Exploitation’. The goal to benefit from complementary capabilities each machine in coordinated way and help developing scientific output scalable future largre machines. programme this ensures that ASDEX Upgrade, MAST-U, TCV, WEST JET (since 2022) work together achieve objectives Missions 1 2 Roadmap: i) demonstrate plasma scenarios...
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....
For electron cyclotron current drive-based stabilization of neoclassical tearing modes (NTMs), it is crucial that the deposition occurs as close to island possible; hence, its location needs be accurately known. An NTM, rotating in laboratory frame, causes fluctuations magnetic flux measurable by Mirnov coils (dB/dt). Temperature perturbations vicinity an NTM are caused displaced surfaces and thus have same frequency signal but show a constant phase difference, which depends on mode topology...
Recent experiments on the ASDEX Upgrade tokamak aim at improving physics base for ITER and DEMO to aid machine design prepare efficient operation. Type I edge localized mode (ELM) mitigation using resonant magnetic perturbations (RMPs) has been shown low pedestal collisionality . In contrast previous high ν* regime, suppression only occurs in a narrow RMP spectral window, indicating process, concomitant confinement drop is observed due reduction of top density electron temperature. Strong...
Non-inductive advanced Tokamak scenarios are a possible way for future nuclear fusion power plants to run in non-pulsed operation.In these scenarios, the ohmic current is replaced on one hand with driven by external sources such as NBI and ECRH other substantial bootstrap-current.The bootstrap produced presence of pressure gradients.This means, increase bootstrap-current-fraction, it advantageous have regions where ITG turbulence reduced.To be able extrapolate from non-inductive done smaller...