Small vacancy dislocation loops in neutron-irradiated copper

Abstract
The present note reconsiders the question of the nature of the ‘black dots’ observed in neutron-irradiated copper by transmission electron microscopy, emphasizing the results obtained by measuring the depth positions of the defects in the foils by quantitative stereo microscopy. The discrepancies between the authors’ results and those recently obtained by McIntyre (1967 a, b) are critically discussed. The previous conclusion that the defects observed in the authors’ work are of vacancy type is upheld.