A5061879545- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
- Laser-Plasma Interactions and Diagnostics
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Nuclear reactor physics and engineering
- Semiconductor materials and interfaces
- Advanced Materials Characterization Techniques
- Magnetic Properties and Applications
- Quantum, superfluid, helium dynamics
- High-pressure geophysics and materials
- Graphite, nuclear technology, radiation studies
- Metallurgical Processes and Thermodynamics
- Ultrasonics and Acoustic Wave Propagation
- Magnetic Properties of Alloys
- Thermography and Photoacoustic Techniques
- Thermal properties of materials
- Radiation Effects in Electronics
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
Max Planck Institute for Plasma Physics
2017-2025
Max Planck Society
2017-2021
Ludwig-Maximilians-Universität München
2020
Technical University of Munich
2015-2019
Harbin Institute of Technology
2016
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...
An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State the art rooms (MSRs) consist up to seven layers high permeability materials combination highly conductive shields. Proper equilibration is crucial obtain such low fields small gradients any MSR. Here we report a scheme equilibrate MSRs 10 times reduced duration sequence significantly lower field improved homogeneity. For search...
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 minimization of the remanent magnetization ferromagnetic materials is a prerequisite for reproducible low magnetic field inside shields. To realistically describe this so-called equilibration procedure, paper proposes two approaches calculation time- and space-dependent fields in presence like permalloy. first method based on Jiles-Atherton model also takes into account frequency dependent effects. second newly developed empirical phase shift model, tailored specially simulation...
Abstract In electron (cyclotron) heated plasmas, in both ASDEX Upgrade ( L -mode) and Wendelstein 7-X, clamping of the ion temperature occurs at T i ∼ 1.5 keV independent magnetic configuration. The ions such plasmas are through energy exchange power as <?CDATA ${n}_{\mathrm{e}}^{2}({T}_{\mathrm{e}}-{T}_{\mathrm{i}})/{T}_{\mathrm{e}}^{3/2}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mi>n</mml:mi> </mml:mrow>...
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...
Low-activation steels are attractive candidates for wall materials in future nuclear-fusion power plants. Through a process called preferential sputtering, an enriched tungsten (W) layer is expected to develop on these steels, lowering erosion and thus increasing their lifetime reducing contamination of the fusion plasma. However, sputtering may be counteracted by interdiffusion W iron (Fe). In this article, we investigate simplified model system such low-activation with W-rich surface,...
Abstract The electron cyclotron resonance heating (ECRH) system of the ASDEX Upgrade tokomak has been upgraded over last 15 years from a 2 MW, s, 140 GHz to an 8 10 dual frequency (105/140 GHz). power exceeds L/H threshold by at least factor two, even for high densities, and roughly equals installed ion range frequencies power. both wave systems together (>10 MW in plasma) is about half available neutral beam injection (NBI) power, allowing significant variations torque input, shape...
Transport analysis of a fully non-inductive high performance ASDEX Upgrade (AUG) hybrid mode discharge (A.Bock, Nuclear Fusion, 2017) is performed using gyro-fluid transport code and gyro-kinetic stability code.It shown that the confluence several mechanisms essential for improvement in core confinement.In addition to rotation shear, low magnetic which common characteristic near axis scenario, found be favorable both electromagnetic α stabilization.Together they facilitate conditions fast...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRadicals bonded to porous Vycor glassE. Melamud, M. G. Reisner, and U. GarbatskiCite this: J. Phys. Chem. 1973, 77, 8, 1023–1027Publication Date (Print):April 1, 1973Publication History Published online1 May 2002Published inissue 1 April 1973https://pubs.acs.org/doi/10.1021/j100627a012https://doi.org/10.1021/j100627a012research-articleACS PublicationsRequest reuse permissionsArticle Views35Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views...
Abstract Advanced Tokamak (AT) scenarios are attractive candidates for future nuclear fusion power plants. These often feature peaked temperature profiles, suggesting a local reduction of turbulent transport. The mechanisms behind this are, as yet, not fully understood. Parameters that thought to be connected these transport reductions include the q -profile and E × B -shear <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>ω</mml:mi>...
On ASDEX Upgrade a prioritized ‘advanced Tokamak’ program has been run during the last two experimental campaigns, focusing on effect of non-standard current profiles behavior high beta plasmas. Two lines (i.e. non-sawtoothing) q-profiles are followed: (1) plasma self-organization centrally flat ( q min ≈ 1) via ‘flux pumping’, here based naturally occurring continuous (1,1) mode and (2) externally shaped with > 1, allowing for more freedom q-profile to be established. The advantages...