Dislocation mechanism of deuterium trapping and transport in tungsten under sub-threshold plasma implantation

We develop a model for D retention in W alloys based on deuterium trapping at dislocations and transport to the surface via the dislocation network with parameters evalu-ated by ab initio calculations. The model can explain ex-perimentally observed trends of D retention in W under sub-threshold implantation, which does not produce stable defects that act as D traps in conventional models. Satura-tion of D retention with implantation dose and effects due to alloying W with Ta are evaluated and compared with experimental observations under low and high flux plasma implantation conditions.