Effect of sink strength dispersion on cluster size distributions simulated by cluster dynamics

Abstract The microstructure evolution in irradiated materials can be conveniently modelled, at large scale, by cluster dynamics (CD). In this approach, the effect of the local environment of defect clusters is neglected. In this article, we first check the validity of this assumption by comparing CD to object kinetic Monte Carlo (OKMC) simulations. We show that for microstructures produced under irradiation, taking into account in CD only the average dependency of clusters’ growth rate on volume fraction does not permit to reproduce reference OKMC results. Accordingly, the sink strength dispersion, quantified using OKMC, is introduced in CD, using a new formalism depending on the Voronoi volumes of defect clusters. CD calculations including sink strength dispersion are shown to be in better agreement with reference OKMC simulations and experimental observations than are classical CD calculations.