Simulations were made of the defect microstructures which resulted from the bombardment of Pb with 180keV Er+ at liquid N temperatures, followed by isochronal annealing at up to 350K. The simulation involved coupled molecular dynamics and kinetic Monte Carlo calculations that followed the production and migration of defects during irradiation and subsequent isochronal annealing. Defect diffusivities and cluster energetics were calculated by means of molecular dynamics simulations, with an embedded atom-like potential for Pb, or were obtained from available experimental data. The primary stage of damage which was produced by energetic recoils was also calculated by using molecular dynamics methods. These calculations revealed the formation of dense interstitial and vacancy clusters, following cooling of the cascade. The ions were implanted at 94K, and the damage was annealed by increasing the temperature in a step-wise manner (50K per 5min). The time-temperature evolution of the density of point defects and defect clusters was calculated, and the results were compared with experimental observations for the same bombardment and annealing conditions. Transmission electron micrographs, taken at various times during annealing, revealed the presence of loops after bombardment at 94K, an increase in loop density with temperature and the disappearance of all loops at 340K. These results supported the simulations.

Heavy Ion Irradiation and Annealing of Lead - Atomistic Simulations and Experimental Validation. M.J.Caturla, M.Wall, E.Alonso, T.Diaz de la Rubia, T.Felter, M.J.Fluss: Journal of Nuclear Materials, 2000, 276, 186-93