High voltage electron and helium irradiation of molybdenum

High purity molybdenum was irradiated with 1.1 MeV electrons, or 100 keV He⁺¹ ions, or both simultaneously at temperatures of 800, 850 and 900°C. Voids were observed only at 900°C 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 850°C. He implantation alone at 900°C produced a large number density of small loops, and no visible voids/bubbles.