Irradiation-induced vacancy injection at surfaces and its effect on the saturation of void swelling

Dynamic vacancy injection into a solid due to the intersection of replacement-collision sequences with surfaces is discussed in the context of the production of voids in metals during irradiation. The basic equations governing the growth of voids in such an environment are derived in the context of the rate theory of swelling. Depending upon the parameters chosen, the model predicts a saturation in the void radius and hence a saturation in swelling. The predictions are compared with observations in order to empirically evaluate the vacancy injection parameter. Finally, the conditions under which saturation is most likely to occur are briefly discussed. (Auth.)