Void formation in heavily irradiated NaCl

Experimental and theoretical results are presented on the formation of void s discovered recently in heavily irradiated NaCl. Experimental data show th at for NaCl samples with particular dopants, the development of radiation d amage, such as Na-colloids, chlorine inclusions and voids does not show a s aturation as a function of the dose. A quantitative comparison of the new m odel (Dubinko et al.. These proceedings) for radiation damage in alkali hal ides with experimental data is presented. Mean sizes and volume fractions o f all types of observed defects are calculated. It is shown that voids form ed due to agglomeration of F centers and cation vacancies can grow to the d imensions exceeding the mean distance between colloids and bubbles, eventua lly absorbing them, and, hence, bringing the halogen gas and metal to a bac k reaction. Impurities are shown to play a major role in the void developme nt with increasing irradiation dose, which strongly affects the radiation s tability of NaCl.