Effect of pre-damage induced by argon ions on the deuterium blister formation in tungsten-tantalum alloys exposed to deuterium plasma

Abstract

This work aims to investigate the effects of 800 keV argon ions pre-damage on the following deuterium plasma irradiation behavior in tungsten-tantalum alloy (5 wt% tantalum dopant). The un-damaged and pre-damaged W–5%Ta were exposed to 60 eV deuterium plasma at a fluence of 1.944 × 1026 D/m2 in the linear plasma device. The results suggest that pre-damaged induced by Ar8+ ions can effectively mitigate deuterium-induced blistering, while the deuterium retention is significantly higher as compared to the un-damaged W–5%Ta. According to the transmission electron microscopic (TEM) analysis, a large number of defects can be observed clearly after irradiation by 800 keV Ar8+ ions, such as vacancies and dislocation loops, which eventually affect the surface blistering and deuterium retention in W–5%Ta. Furthermore, we also compared the deuterium retention in pre-damaged pure W, which was significantly increased by a factor of 15 than in pre-damaged W–5%Ta.