Positron trapping at voids in metals: a generalized model

A general semi-classical model for describing positron trapping at voids in metals is presented. We show how the positron trapping rate increases linearly with temperature from a non-zero value at zero temperature. The model shows that information about the void radius is present in the temperature-dependent part of the trapping rate, and it is found to be consistent with observation in which void size and density have been determined by other techniques. (author)