High voltage electron and helium irradiation of molybdenum

High purity molybdenum was irradiated with MeV electrons, or 100 keV He ions, or both simultaneously at temperatures of 800, 850 and 9000C. Voids were observed only at 9000C in low dose electron irradiations, while vacancy loops were formed at the lower irradiation temperatures. Simultaneous He and electron bombardment produced small defect clusters at 8500C. He implantation alone at 9000C produced a large number density of small loops, and no visible voids/bubbles. (orig.)