Cluster dynamics simulation of deuterium retention behaviors in irradiated beryllium

Abstract

The retention behaviors of deuterium (D) in beryllium (Be) are investigated using a spatially resolved cluster dynamics model under different irradiation conditions. The trapping effects of deuterium (D) in the forms of D atoms, D₂ molecules and D with vacancy complex clusters (D_mV) play the most important role in the behaviors of D retention in bulk Be under irradiation of 9 keV D ions. The fraction of D₂ in the total D retention increases with the increase in ion influence, due to the chemical reaction rate enhancement between D atoms with high density. The increases in both ion incident angle and Be bulk temperature reduce the retention of D_mV complex clusters by increasing the D desorption rate. In addition, the neutron synergistic irradiation changes the D retention profiles, especially in the recombination region, by introducing extra defect sinks. These results can improve the understanding of the mechanisms of D diffusion, accumulation and retention in irradiated Be.