Kinetics of interstitial loop formation in irradiated metals containing pre-existing dislocations

The theory of interstitial loop nucleation and growth in metals at the beginning of irradiation is developed. After some transient time the loop concentration becomes constant and both interstitial and vacancy diffusion fluxes achieve their steady state values. At this stage vacancy cluster nucleation becomes possible. Analytical expressions for the loop concentration, the characteristic times of their growth and the start for vacancy clustering are obtained. It is shown that for given irradiation conditions some critical density of dislocation network exists. For higher densities the process of loop formation under irradiation is suppressed due to interstitial absorption in sinks. (author)