Characterization of Near-surface He Bubble Behavior in SiC*

Silicon carbide (SiC) is currently a promising fusion material due to its excellent thermo-mechanical/chemical properties, irradiation tolerance, and low-activation. As a plasma-facing material, the copious amounts of He produced from implantation and high energy neutron transmutation could be detrimental towards property integrity. This work utilizes molecular dynamics simulations to characterize He bubble stability and bursting with temperature dependence accounted for. Relationships between pressure, bubble size, and He-vacancy ratios are used to determine onset of bubble bursting. This is important not only for SiC property stability but also on He recycling. Additionally, we explore the influence of He bubbles on hydrogen retention by looking at species distributions relative to He bubble location. This information is important in understanding retention and recycling of H within SiC when used as a plasma-facing material. Finally, the He bubble behavior is compared to previous findings for tungsten to better characterize the SiC response.