TY  - JOUR
AU  - Gago, Mauricio
AU  - Kreter, Arkadi
AU  - Unterberg, Bernhard
AU  - Wirtz, Marius
TI  - Bubble Formation in ITER-Grade Tungsten after Exposure to Stationary D/He Plasma and ELM-like Thermal Shocks
JO  - Journal of nuclear engineering
VL  - 4
IS  - 1
SN  - 2673-4362
CY  - Basel
PB  - MDPI
M1  - FZJ-2023-01430
SP  - 204 - 212
PY  - 2023
AB  - Plasma-facing materials (PFMs) in the ITER divertor will be exposed to severe conditions, including exposure to transient heat loads from edge-localized modes (ELMs) and to plasma particles and neutrons. Tungsten is the material chosen as PFM for the ITER divertor. In previous tests, bubble formation in ITER-grade tungsten was detected when exposed to fusion relevant conditions. For this study, ITER-grade tungsten was exposed to simultaneous ELM-like transient heat loads and D/He (6%) plasma in the linear plasma device PSI-2. Bubble formation was then investigated via SEM micrographs and FIB cuts. It was found that for exposure to 100.000 laser pulses of 0.6 GWm−2 absorbed power density (Pabs), only small bubbles in the nanometer range were formed close to the surface. After increasing Pabs to 0.8 and 1.0 GWm−2, the size of the bubbles went up to about 1 µm in size and were deeper below the surface. Increasing the plasma fluence had an even larger effect, more than doubling bubble density and increasing bubble size to up to 2 µm in diameter. When using deuterium-only plasma, the samples showed no bubble formation and reduced cracking, showing such bubble formation is caused by exposure to helium plasma.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001188658700001
DO  - DOI:10.3390/jne4010016
UR  - https://juser.fz-juelich.de/record/1005321
ER  -