On the recovery of aluminium after neutron irradiation at 78°K

Abstract
The recovery after neutron irradiation at 78°K of annealed and vacancy doped Al 99.995% purity, has been compared with the recovery observed after quenching from 600°c; from the analysis of the results it appears that stage III (160 to 280°K) can be fairly well interpreted as due to the migration of single vacancies to interstitial clusters formed at the irradiation temperature. Since this interpretation is in contrast with the point of view advanced by other authors, who assume that interstitial defects move in stage III, a new analysis of the low temperature recovery stages is advanced. From a comparison of the results of several investigators it appears that all experimental results can be fairly interpreted by the assumption that crowdions move at about 34°K and that normal interstitials move at about 80°K. Both the interstitials interact selectively with impurities and have a large tendency to form stable clusters, which can be eliminated only at higher temperatures (during stage III) by the migration of single vacancies.