A5078915437- Fusion materials and technologies
- Magnetic confinement fusion research
- Nuclear Materials and Properties
- Ion-surface interactions and analysis
- Metal and Thin Film Mechanics
- Superconducting Materials and Applications
- Advanced Materials Characterization Techniques
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Hydrogen Storage and Materials
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Ionosphere and magnetosphere dynamics
- Muon and positron interactions and applications
- Electron and X-Ray Spectroscopy Techniques
- Semiconductor materials and devices
- Advanced Chemical Physics Studies
- Cold Fusion and Nuclear Reactions
- Advanced materials and composites
- Catalytic Processes in Materials Science
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Copper Interconnects and Reliability
- Metal Alloys Wear and Properties
Max Planck Institute for Plasma Physics
2013-2025
Royal Military Academy
2020
Max Planck Society
2009-2019
Max Planck Computing and Data Facility
2019
This paper reports the impact on confinement and power load of high-shape 2.5 MA ELMy H-mode scenario at JET a change from all carbon plasma-facing components to an metal wall. In preparation this change, systematic studies reduction as result fuelling in combination with nitrogen seeding were carried out JET-C are compared their counterpart metallic An unexpected significant is reported decrease pedestal but partially recovered injection nitrogen.
The retention of 1 keV D + ions implanted into clean and oxidized single crystalline Be at room elevated temperatures is investigated by a combination in situ analytical techniques including temperature programmed desorption (TPD), nuclear reaction analysis, low-energy ion spectroscopy (LEIS) x-ray photoelectron spectroscopy.For the first time, whole regime for deuterium release influence thin oxide films on processes are clarified.The cleaned annealed sample has residual oxygen...
Plasma catalysis has drawn attention in the past few decades as a possible alternative to Haber-Bosch process for ammonia production. In particular, radio frequency plasma assisted advantage of its adaptability industrial scale. However, years, very experimental studies have focused on synthesis from nitrogen/hydrogen plasma. As consequence, date, there been little agreement about complex mechanisms underlying plasma-catalyst interactions. Gaining such an understanding is therefore essential...
Numerous experiments have been performed in the past few years on solid hydride deposition under beryllium-seeded plasma action or energetic hydrogen implantation into metallic beryllium. This article reports calculations carried out using first-principles density functional theory (DFT) and discusses results with respect to thermal desorption experiments. The structures of amorphous beryllium were investigated for various H/Be ratios. They compared structure organized BeH2 crystal as a test...
The former all-carbon wall on JET has been replaced with beryllium in the main torus and tungsten divertor to mimic surface materials envisaged for ITER. Comparisons are presented between type I H-mode characteristics each design by examining respective scans over deuterium fuelling impurity seeding, required ameliorate exhaust loads both at full capability Attention is focused upon a common high-triangularity, single-null configuration 2.5 MA, q95 ≈ 3.5 yielding most robust all-C...
Global gas balance experiments at ASDEX Upgrade (AUG) and JET have shown that a considerable fraction of nitrogen injected for radiative cooling is not recovered as N2 upon regeneration the liquid helium cryo pump. The most probable loss channels are ion implantation into plasma-facing materials, co-deposition ammonia formation. These three mechanisms investigated in laboratory tokamak by numerical simulations. Laboratory ions beryllium tungsten leads to formation surface nitrides, which may...
The influence of surface roughness on the sputter yield was investigated as a function angle incidence. In this work, nm-smooth and rough samples with roughnesses µm length scale were produced by depositing thin Fe W films smooth Si substrates via magnetron sputtering. morphology determined atomic force microscopy. exposed to 6 keV D3+ ion beam (2 keV/D) under various angles incidence ranging from 0° 75° respect normal fluences order 1022 D/m2. layer thickness measured Rutherford...
Ammonia formation was studied in a series of dedicated nitrogen seeded H-mode discharges at ASDEX Upgrade.The evolution ammonia investigated with reference phase before the seeding, and long, stable flat-top nitrogen-seeded phase.It monitored divertor spectroscopy analysis exhaust gas.The amount detected increased continuously over course five same seeding rate.The trend observed density core plasma, as measured by charge exchange recombination other signals, linked to effects seeding.The...
Tungsten (W) will be used as material for plasma-facing components (PFCs) in the divertor of ITER and interact with Helium (He) ions either from initial He plasma operation or Deuterium-Tritium (DT) fusion reactions active phase.Laboratory experiments reported that a specific operational window impact energy, ion fluence, andmodification W surfaces occurs resulting formation He-induced nanostructures.Experiments ASDEX Upgrade H-mode plasmas (B t = 2.5T, I p 0.8M A, P aux ≃ 8.0M ) have been...
We have investigated net and gross erosion of W in the outer strike-point (OSP) region ASDEX Upgrade with help marker probes during low-density/high-temperature L-mode discharges. Post mortem analyses indicate net-erosion rates 0.04–0.13 nm s−1, highest measured close to OSP. Re-deposition was some 30–40% erosion, which is lower than what has earlier been obtained spectroscopically (∼50–60%), possibly due special plasma conditions our experiment intense flux atoms originating from main...
EUROFER is a Reduced Activation Ferritic Martensitic (RAFM) steel developed as structural material for future fusion power plants and considered first-wall in recessed areas of DEMO. Recent work has shown fluence-dependent decrease the sputter yield bombardment with deuterium ions energy range 100 to about 500 eV. This was previously attributed preferential sputtering lower mass constituents EUROFER, such Fe Cr, compared higher alloying elements. leads an increase surface tungsten...
Recent successful experiments with nitrogen as a seeding gas in fusion plasma devices, together the decision to use beryllium an armor material international experiment ITER, have triggered interest interactions of energetic N ions Be and influence possible compound formation on parameters relevant reactor operation safety. Laboratory are performed investigate properties 'mixed material' formed upon bombardment bulk (keV) ions. The nitride within implantation zone few nanometres is observed...
Plasma-wall interactions have been studied in the full-W ASDEX Upgrade during its dedicated helium campaign. Relatively clean plasmas with a He content of >80% could be obtained by applying ion cyclotron wall conditioning (ICWC) discharges upon changeover from D to He. However, co-deposited layers significant amounts and were measured on W samples exposed ICWC at low-field side (outer) midplane. This is sign local migration accumulation materials residual fuel regions shadowed direct plasma...
In the ITER tokamak, injection of nitrogen is foreseen to decrease heat loads on divertor surfaces. However, once dissociated, atoms react with hydrogen isotopes form ammonia isotopologues. The formation tritiated may pose some issues regards tritium inventory and operation duty cycle. this paper, we report a study effect three parameters relevance for fusion environment production, including presence catalytic surface, sample temperature noble gas addition. Results from N2/H2 RF plasma...
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,...
The erosion behaviour of EUROFER steel due to mono-energetic deuterium (D) ion bombardment in the energy range 100–1000 eV/D was investigated. At low fluences, sputtering yield is comparable that pure iron (Fe). It then decreases with increasing fluence and tends toward a steady state at larger fluences. largest experimentally investigated fluences are order several 1024 D/m2. reduction more pronounced for lower D impinging energies. A simple model presented within which evolution can be...