PNNL

Abstract

Early experimental data on void swelling in electron-irradiated materials disagree with the dislocation bias models based on the dislocation-point defect elastic interactions. Later this became one of the reasons that prompted the development of models based on production bias (PBM) as the main driver for swelling, which assumed that the dislocation bias was much lower than that predicted by theory. However, the PBM in its present form fails to account for important and common observations: the indefinite void growth often observed under cascade irradiation and the swelling saturation observed under high dose irradiation and in void lattices. In this paper we show that these contradictions can be naturally resolved in the framework of the rate theory modified with account of the radiation-induced vacancy emission from extended defects, such as voids, dislocations and grain boundaries. The modified rate theory agrees well with the experimental data, which proves that original dislocation bias should be used in rate theory models in different irradiation. The modified theory predictions include (but not limited to) the radiation-induced annealing of voids, swelling saturation under high dose irradiation, generally, and in void lattices, in particular.