The characteristics of radiation-induced defects in high-purity material, when subjected to MeV electron irradiation at 77K, were studied by means of electrical resistivity recovery measurements. After the lowest electron doses, stage II consisted of 2 sub-stages; at 165 and 180K. With increasing dose, the 165K stage remained fixed while the 180K stage shifted to lower temperatures. These sub-stages were attributed to the free migration of di-interstitials inside and outside the displacement cascade, respectively. For higher electron doses, a slight sub-stage (180-190K) was thought to be associated with the correlated annihilation of vacancies which was observed after fast neutron irradiation. Another marked stage (210 to 240K), with a dose-dependence of the peak temperature shift, was attributed to monovacancy migration. From these results, it was confirmed that the radiation damage which was produced by 30MeV electrons comprised 2 types of defect structure. One was associated with displacement cascades, while the other was associated with simple displacement processes.

Recovery of Electrical Resistivity of High-Purity Iron Irradiated with 30MeV Electrons at 77K. H.Abe, E.Kuramoto: Journal of Nuclear Materials, 2000, 283-287, 174-8