Molecular dynamics simulations of cascades in the a-phase were used to predict the concentration of freely migrating defects. Single self-interstitial atoms were recognized as being important because they were more remote from the cascade, and their migration energies were lower than those of single vacancies. It was therefore possible to estimate the enhanced concentration of freely migrating interstitial defects as a function of the neutron energy spectrum and the temperature. Algorithms which described the temperature effect for a given neutron energy spectrum were incorporated into a model for the radiation-induced grain boundary segregation of P in a-Fe. This led to improved predictions of the temperature dependence of segregation.

Neutron Energy Spectrum and Temperature Effects on Freely Migrating Defect Concentrations and Grain Boundary Segregation in a-Fe. R.G.Faulkner, D.J.Bacon, S.Song, P.E.J.Flewitt: Journal of Nuclear Materials, 1999, 271-272, 1-6