Influence of Fluctuations of the Point-Defects’ Generation Rate and Inhomogeneity of Irradiated F.C.C. Crystal on the Temperature Dependence of the Dissipative-Structure Period in a Spatial Distribution of Radiation Vacancies

A kinetic model for the influence of external noise, such as fluctuations of the point-defects’ production rate and inhomogeneity of irradiated f.c.c. crystal, on the formation of modulated defect-distribution structure is considered. Defect-production rate and density of sinks for point defects are simulated as independent uniform and stationary stochastic fields with certain parameters. The interaction between vacancies is taken into account. Such stochastic fields can induce a spatial point-defects’ distribution, which is a stationary uniform stochastic field. Its mean value and correlation functions are estimated, and restricting conditions are determined when this stochastic field becomes unstable because of interaction between defect-density fluctuations and a stochastic field with a spatially-periodic mean value is formed. A formula for evaluating its spatial period is analysed. This geometrical parameter of such a dissipative structure is determined also by kinetic characteristics.