The effects of helium on irradiation damage in single crystal iron

Fusion systems have a major issue with the relatively large amounts of helium (He) which are generated during the irradiation damage process. The effect of helium on the accumulation of defects and defect clusters and the influence of the resulting microstructure on physical and mechanical properties has been the focus of a large number of experimental and modeling studies over the past twenty years. The present work is part of an effort to quantify these effects in ways that were not possible in earlier studies. This is accomplished through systematic and coordinated computational modeling and experiments. The modeling approach employs both molecular dynamics (MD) and kinetic Monte Carlo (kMC) simulations to study the dynamic evolution of helium and defect clusters in bcc iron over relevant time scales. The kMC model follows the transport or evolution of the major defect entities in the material.