Simulation of the low-temperature stage of annealing of radiation defects in BCC iron using the molecular dynamics method

Abstract

A procedure for the simulation of the low-temperature stage of annealing of irradiated α iron is suggested. Based on the method of molecular dynamics, the reaction rate constants and the energies of activation for the recombination of Frenkel pairs are calculated. For the simulation of the ID and IE stages, the coefficient of diffusion of interstitials is calculated. The calculations are performed for three different potentials of interaction of iron atoms. All three potentials give close results for the majority of the configurations of Frenkel pairs considered. A comparison of the calculated annealing curve with the experimental curve of the stage I is given. Based on this comparison, a correspondence between different configurations of close Frenkel pairs and peaks of the experimental curve has been established. It is shown that one peak can be associated with several configurations of close pairs.