GENERALIZED RATE THEORY FOR SPATIALLY INHOMOGENEOUS SYSTEMS OF POINT-DEFECT SINKS

A statistical approach to the derivation of rate equations governing the diffusion of point defects to a dilute random system of sinks in a homogeneous matrix is proposed and discussed. The approach clearly reveals a hierarchical nature of the rate theory. A procedure allowing to reduce this hierarchy to the conventional set of rate equations and to introduce self-consistently the concept of sink strength is described in detail. The resulting set of equations can be quite naturally applied to spatially inhomogeneous sink systems, since the usual assumption of homogeneous sink distribution in the matrix is shown to be unessential for the reduction procedure. Finally, the consecutive procedure for calculation of corrections to sink strength due to close sink configurations is proposed and generalization of the rate theory in order to account for effects of elastic point defect interaction with sinks is discussed.