By using the Monte Carlo technique, a model was developed for the atomic-scale simulation of the formation of extended defects under irradiation. Three types of reaction were assumed to occur: vacancy-interstitial recombination, association of point defects to form a new extended defect and reactions of point defects with extended defects which led to the growth of extended defects. Periodic boundary conditions were used to simulate an infinite lattice, and surface effects were ignored. The results were compared with those obtained by using chemical rate theory. It was shown that atomic-scale simulations could lead to microscopic results which could not be reached by solving the usual sets of equations: in particular, the spatial distribution of dislocation loops and the distribution of vacancies around the dislocation loops. It was also shown that a strong correlation existed between the relative positions of extended defects and point defects, and that they affected one another.

Atomic Scale Simulation of the Diffusion and Association Phenomena of Point Defects under Irradiation - Formation and Growth of Dislocation Loops. A.Amghar, H.Idrissi-Saba, M.Djafari-Rouhani, A.M.Gue, D.Estève: Physica Scripta, 2001, 64[1], 75-83