SMuK 2021 – scientific programme
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P: Fachverband Plasmaphysik
P 17: Poster II
P 17.29: Poster
Friday, September 3, 2021, 14:00–16:00, P
Early stages of He cluster formation in tungsten single crystals — •Annemarie Kärcher1,2, Vassily V. Burwitz2, Thomas Schwarz-Selinger1, and Wolfgang Jacob1 — 1Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany — 2Technische Universität München, 85747 Garching, Germany
Tungsten (W) has been established as a main candidate for plasma-facing materials (PFMs) in future nuclear fusion reactors due to its favorable properties regarding the fusion environment. As PFM, tungsten will be subjected to intense impinging fluxes of helium (He). While the consequences of high He fluxes on the surface of tungsten materials have already been thoroughly studied, the mechanisms behind the early stages of the He cluster formation are still unclear. In order to understand the initial steps of the interaction of He with W, especially the impact of pre-existing defects, defined defects are induced in W111 single crystals and characterized by positron annihilation spectroscopy (PAS). Then, these are exposed to a low-temperature He plasma using an implantation energy below the displacement theshold. These He implanted samples are measured by PAS, elastic recoil detection analysis and thermal desorption spectroscopy. The experimental results are compared to simulation data.