Evolution of damage structures under 14 MeV neutron, 4 MeV Ni ion and 1.25 MeV electron irradiation

Mo, Fe, Cu and Ni were irradiated with 14 MeV neutrons and 4 MeV Ni ions between 250C and 4000C. Some of the specimens were re-irradiated by a HVEM to know the nature of the radiation-induced clusters. One of the characteristic features of cascade damage was enhanced formation of interstitial loops near dislocation lines. Stacking fault tetrahedra and vacancy loops were formed in fcc metals irradiated by neutrons and in Fe irradiated by Ni ions, respectively. These cascade effects made the microstructure complicated. And thus they should shift the void swelling peak to the high temperature side. (orig.)