B. Schweer
A5019146330- Magnetic confinement fusion research
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Atomic and Molecular Physics
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Nuclear Materials and Properties
- Metal and Thin Film Mechanics
- Nuclear Physics and Applications
- Diamond and Carbon-based Materials Research
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Ion-surface interactions and analysis
- Electromagnetic Compatibility and Measurements
- Atomic and Subatomic Physics Research
- Graphite, nuclear technology, radiation studies
- Astro and Planetary Science
- Metallurgical Processes and Thermodynamics
- Quantum Chromodynamics and Particle Interactions
- Advanced Antenna and Metasurface Technologies
- Nuclear physics research studies
- Antenna Design and Analysis
Royal Military Academy
1993-2023
Forschungszentrum Jülich
2011-2020
University of Wisconsin–Madison
2016-2018
Huazhong University of Science and Technology
2018
Institute of Plasma Physics
2018
Chinese Academy of Sciences
2018
Osaka University
2017
Kyushu University
2009-2017
KTH Royal Institute of Technology
2017
Culham Science Centre
2006-2016
The linear plasma device PSI-2 serves as a pilot experiment for the development of components, operational regimes and control systems JULE-PSI, which will be located in nuclear environment allowing studies radioactive toxic samples. is also used fusion reactor relevant plasma-material interaction studies. This contribution describes layout parameters summarizes recent scientific technical progress project, including installation target station sample manipulation analyses.
Analysis and understanding of wall erosion, material transport fuel retention are among the most important tasks for ITER future devices, since these questions determine largely lifetime availability fusion reactor. These data also extreme value to improve validate models in vessel build-up T inventory D–T devices. So far, research areas is supported by post-mortem analysis tiles. However, access samples will be very much restricted next-generation devices (such as ITER, JT-60SA, W7-X, etc)...
Experimental results from TEXTOR are presented to provide strong evidence for the feasibility of 'cold radiative plasma mantle', a concept which might be possible solution energy exhaust problem in fusion reactor. The is compared with high density divertor. compatibility other constraints, limitations and open problems discussed, particular issues stationarity (feed-back control, thermal instabilities, q=2), confinement, He-exhaust fuel dilution.
The next step in the Wendelstein stellarator line is large superconducting device 7-X, currently under construction Greifswald, Germany. Steady-state operation an intrinsic feature of stellarators, and one key element 7-X mission to demonstrate steady-state plasma conditions relevant for a fusion power plant. device, on hand, requires implementation special technologies, giving rise technical challenges during design, fabrication assembly such device. On other also physics development at...
Cracking thresholds and crack patterns in tungsten targets after repetitive ITER-like edge localized mode (ELM) pulses have been studied recent simulation experiments by laser irradiation. The specimens were tested under selected conditions to quantify the thermal shock response. A Nd:YAG capable of delivering up 32 J energy per pulse with a duration 1 ms at fundamental wavelength λ = 1064 nm has used irradiate ITER-grade samples heat loads. exposures performed for room temperature (RT) as...
The chemical erosion of carbon in interaction with a hydrogen plasma has been studied detail ion beam experiments, and yield values are available as function energy surface temperature.However, the conditions ITER divertor cannot be simulated by especially far flux is concerned.Therefore, joint attempt was made through EU Task Force on plasma-wall international tokamak physics activity involving seven different fusion devices simulators to clarify dependence.For each data point local were...
Beam emission spectroscopy on thermal helium is used at the TEXTOR tokamak as a reliable method to obtain radial profiles of electron temperature Te(r, t) and density ne(r, t). In this paper experimental realization status atomic physics employed well major factors for measurement's accuracy are evaluated. On side, hardware specifications described impact beam atoms local plasma parameters shown be negligible. modeling side collisional–radiative model (CRM) applied infer ne Te from measured...
At the TEXTOR tokamak an external resonant magnetic perturbation is applied with dynamic ergodic divertor to control edge transport properties. The approaches analyse impact of such a kind stochastization on apply mostly shell-like picture which includes dependence from field topology in radial direction only. In this paper multiple experimental evidence presented contrast these forms poloidally heterogenous layer characteristics are determined by alternating line behaviour. A thorough...
The Wendelstein 7-X (W7-X) optimized stellarator fusion experiment, which went into operation in 2015, has been operating since 2017 with an un-cooled modular graphite divertor. This allowed first divertor physics studies to be performed at pulse energies up 80 MJ, as opposed 4 MJ the phase, where five inboard limiters were installed instead of a This, and number other upgrades device capabilities, extension regimes higher plasma density, heating power, performance overall, e.g. setting new...
The investigation of edge plasmas at the stellarator W7-X requires a flexible tool for integration variety different diagnostics as e.g. electrical probes, probing magnetic coils, material collection, or exposition and gas injection. A multi-purpose manipulator (MPM) system has been developed attached to vessel before operational phase 1.1. was designed user facility many diagnostics, which can be mounted on unique interface without breaking vacuum. system, located in equatorial plane,...
Coating of the walls TEXTOR with silicon has led to improved tokamak plasma performance. Very low concentrations C, B, and O are measured. Radiation from is located at periphery r/a\ensuremath{\ge}0.75 decreases increasing density. Density limits enhanced by 30% as compared boronized conditions; large density gradients electron temperatures edge (10 eV) obtained. The confinement regimes observed earlier densities...
The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating m/n=3/1 mode configuration, are presented. deeply penetrating external magnetic field perturbation this configuration increases toroidal plasma rotation. Staying below excitation threshold for m/n=2/1 tearing mode, rotation is always direction current, even if projection rotating opposite direction. observed consistent with a radial electric field, generated by an enhanced electron transport ergodic layers near...
A new endoscope with optimised divertor view has been developed in order to survey and monitor the emission of specific impurities such as tungsten remaining carbon well beryllium JET after implementation ITER-like wall 2011. The is a prototype for testing an ITER relevant design concept based on reflective optics only. It may be subject high neutron fluxes expected ITER. operating wavelength range, from 390 nm 2500 nm, allows measurements all (W I, Be II, C III) optical transmittance (≥30%...
The new JET ITER-like wall (made of beryllium and tungsten) is more fragile than the former carbon fiber composite requires active protection to prevent excessive heat loads on plasma facing components (PFC). Analog CCD cameras operating in near infrared wavelength are used measure surface temperature PFCs. Region interest (ROI) analysis performed real time maximum measured each ROI sent vessel thermal map. system started October 2011 has already successfully led a safe landing when hot...
Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters December 2015. At end of 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were operation, allowing detailed studies many interesting plasma phenomena. For example, fast neutral gas manometers supported video cameras (including one fast-frame camera frame rates...
The radiative improved (RI) mode is a tokamak regime offering many attractive reactor features. In the article, RI of TEXTOR-94 shown to follow same scaling as linear ohmic confinement and thus identified one most fundamental operational regimes. current understanding derived from experiments modelling conditions necessary for sustaining reviewed, are mechanisms leading L-RI transition. article discusses compatibility high impurity seeding with low central power density burning reactor, well...
Limiter experiments with a Mo test limiter have been carried out in TEXTOR under various conditions ohmic and NBI heating. Maximum power loads reached about 20 MW/m2 resulting surface temperatures up to the melting point. A maximum fraction of 8% total convective energy plasma was deposited onto limiter. Molybdenum impurities are mainly produced by physical sputtering due impact C O impurities. Under heating impurity radiation increased increasing density, though relative source strength...
Abstract Profiles of the Balmer lines D a ( H ), β ) and γ have been measured in scrape‐off layer within edge TEXTOR (upgrade) plasma, under Ohmic conditions with neutral‐beam injection. Each line profile shows strong Zeeman effect vicinity centre, marked central dip when mainly σ components are observed. The core evidently originates from cold atoms excited course molecular dissociation, while broad pedestal on which rests is radiated by produced through charge‐exchange recombination...