Nucleation of interstitial type dislocation loops in metals under neutron irradiation

For the understanding of suppression of the nucleation of interstitial type dislocation loops in metals during cascade damages, four factors are explained and their relative importance is discussed. The first factor is the positional instability of small interstitial clusters. This effect is expected to enhance the dislocation structure development by agglomeration of the embryos, but it is also expected to suppress the formation of loops by easy escape to sinks. The second is the stochastic fluctuation of point defect reactions with embryos. This effect plays an important role when the balanced point defect concentrations is high. The third is the thermal instability of embryos of loops. It is predominant at high temperatures. The last is the cascade localization induced bias (CLIB) effect, which leads a vacancy dominant point defect reactions in a cascade. (author)