THEORY OF BUBBLE MIGRATION APPLIED TO IRRADIATED MATERIALS

Methods of crystal growth are reviewed and then applied to the problem of bubbles migrating in solids. The distribution of driving force between the reversible and irreversible processes occurring at the bubble surface is summarized in a coupling equation which illustrates the contributions made by surface curvature, atomic attachment kinetics, impurities contained within the bubble, and vapor diffusion. The shape assumed by a migrating bubble is reviewed, and the special case in which kinetic effects dominate is examined in detail. Lenticular shaped bubbles are shown to be a form of cellular growth, resulting from the accumulation of impurities within the bubble. The trails of small bubbles behind such voids reveal the entrainment of impurities as in the grooves of a cellular interface. A procedure is briefly described for evaluating bubble shapes and temperature profiles in the matrix when all features such as capillarity, diffusion and kinetics are considered. © 1969.