PNNL

Abstract

Molecular dynamics (MD) methods have been utilized to study the formation of vacancy clusters created by displacement cascades in ?-Fe containing concentrations of substitutional He atoms varying from 1-5%. These He concentrations are not necessarily intended to represent specific conditions within a fusion reactor (average end-of-life He concentrations in the first wall are expected to be on the order of 0.15%), but they provide an opportunity to investigate the effects of substantial amounts of He on cascade processes and microstructure development under damage producing conditions.