Radiation Damage in bcc Metal Nb Studied by Perturbed Angular Correlation and Positron Annihilation Techniques

9 The radiation damage induced by the reactor neutrons in body-centered-cubic metal Nb is simulated by the 81 MeV carbon irradiation to a total dose of 2.5x10¹⁶/cm². The created radiation damage and its thermal annealing behavior are studied by positron annihilation and perturbed angular correlation techniques. The results show the existence of both mono- and di-vacancies in Nb after the irradiation. Most of the defects caused by the radiation damage disappear after annealing around 960K. The radiation damage is completely annealed at 1058K.