2022

Liski, Anna; Vuoriheimo, Tomi; Jalkanen, Pasi; Mizohata, Kenichiro; Lu, Eryang; Likonen, Jari; Heino, Jouni; Heinola, Kalle; Zayachuk, Yevhen; Widdowson, Anna; Tseng, Ko-Kai; Tsai, Che-Wei; Yeh, Jien-Wei; Tuomisto, Filip; Ahlgren, Tommy

High entropy alloys are a promising new class of metal alloys with outstanding radiation resistance and thermal stability. The interaction with hydrogen might, however, have desired (H storage) or undesired effects, such as hydrogen-induced embrittlement or tritium retention in the fusion reactor wall. High entropy alloy WMoTaNbV and bulk W samples were used to study the quantity of irradiation-induced trapping sites and properties of D retention by employing thermal desorption spectrometry, secondary ion mass spectrometry, and elastic recoil detection analysis. The D implantation was not found to create additional hydrogen traps in WMoTaNbV as it does in W, while 90 at% of implanted D is retained in WMoTaNbV, in contrast to 35 at% in W. Implantation created damage predicted by SRIM is 0.24 dpa in WMoTaNbV, calculated with a density of 6.044×1022 atoms/cm3. The depth of the maximum damage was 90 nm. An effective trapping energy for D in WMoTaNbV was found to be about 1.7 eV, and the D emission temperature was close to 700 °C.