Production and annihilation of deuterium traps in He-irradiated vanadium

Deuterium trapping in vanadium pre-irradiated by helium ions was experimentally studied. One side of a vanadium sheet was continuously exposed to deuterium plasma and irradiated by 0.8 MeV 3He ions with a dose of 1.2 × 1021 m−2 to introduce radiation damages. Deuterium depth profiles in the irradiated region were observed by a nuclear reaction analysis. Many traps were produced by the irradiation and the deuterium concentration at 348 K increased to 10 times compare to the concentration before the irradiation. The production rate of the trap to atomic displacement was estimated to be 0.021. The trap was fully annihilated at 523 K. These behaviors suggested that the trap was atom vacancies associated with the radiation damages.