The effect of climb motion on the dislocation bias during irradiation

Abstract

The elastic-field model of a dislocation embedded in a lossy continuum is used to derive, for the first time, self-consistent expressions for the dislocation sink strength suitable for use in the chemical rate theory approach to the study of micro structural evolution during irradiation, when the sensitivity of physical observables (such as void swelling or the dislocation climb rate itself) to the diffusion-controlled dislocation climb motion is required. It is shown that making allowance for climb motion leads to an increase in the dislocation bias factor for vacancies compared with that for interstitials, and to a concomitant reduction of the dislocation net bias and the actual dislocation climb rate. Numerical results are given for a wide range of dislocation densities, neutral sink strengths, temperatures and point-defect production rates, and particular attention is drawn to the significance of climb motion for charged-particle simulation conditions.