Kinetics of nucleation and coarsening of colloids and voids in crystals under irradiation

The kinetics of nucleation and coarsening of vacancy clusters in irradiated crystals are considered with account of their elastic interaction with point defects resulting in the biased absorption of vacancies and interstitial atoms. It is shown that in the technologically important range of high dose rate (or low temperature) irradiation, the nucleation rate and the final number density of clusters are determined by the bias parameters rather than by irradiation conditions. The model is applied to the evolution of sodium colloids and chlorine bubbles in NaCl resulting in the formation of voids followed by a sudden fracture of the material, which presents a potential problem in rock salt nuclear waste repositories. The number densities and mean sizes of colloids, bubbles and voids are evaluated and compared with experimental data.