Effect of additional sinks of point defects on the diffusion interaction of voids. Stability of the void lattice under irradiation

Abstract

A theory of the diffusion interaction of vacancy voids in a many-particle system, i.e. that consisting of N-voids is constructed. The void interaction results from the diffusion exchange of point defects, which are present in the concentration cloud around every void. For a metal containing impurities, dislocations etc. an expression for the growth rate of an individual void of an arbitrary size is obtained within the framework of this model, taking into account the effect of the other voids in it. It is shown that the diffusion interaction in the void system has a certain screening radius, which depends on the total number of voids and additional sinks for point defects in a metal. Using the diffusion interaction of the vacancy voids we have studied the kinetic stability of the lattice void distribution both under continuous irradiation and ordinary temperature annealing. The criterion for the existence of a stable lattice of vacancy voids is obtained in a real crystal containing dislocations and impurity atoms under irradiation conditions. In the void lattice instability range the laws governing the variation in the average void size and dispersion of the void size distribution in a lattice are derived. The estimates of the typical void lattice instability time are presented.