Abstract
The theory of Brown, Kelly and Mayer (1969) intended to explain the effect of boron in the neutron irradiation of graphite should also be relevant to the case of electron damage in metals. When the theory is applied to the recent data of Shimomura (1969) and Makin (1968) it is found to work well in the former case, but to need modification to allow for the foil surfaces in the latter case. These experiments provide a more direct way of determining the behaviour of interstitial atoms in crystals than older methods based on low temperature annealing studies.