Point defect mobility in hydrogen pre-implanted vanadium under electron irradiation

Mobility of point defect (vacancy and interstitial) is a critical factor for irradiation resistance of nuclear materials like vanadium. Hydrogen (H) atoms generated by nuclear transmutation can strongly affect the migration mechanism of point defect. Microstructural evolution and point defect behavior in vanadium with and without H-pre-implantation have been investigated by in-situ annealing and electron irradiation by using high voltage electron microscopy (HVEM). The migration energy of vacancies and the one of interstitials were calculated to be about 1.5 eV and 0.3 eV based on the growth speed and the number density of dislocation loops at 573–773 K, respectively. The surface effect of samples on measurement of migration energy and the interaction between hydrogen and point defect were also discussed.