Abstract
Results are presented from molecular dynamics (MD) simulations of displacement cascades created in -iron (Fe) by primary knock-on atoms (PKAs) with energy from 5 to 20 keV and mass chosen to represent C, Fe and Bi. Molecular Bi2 has also been simulated using two Bi PKAs, and PKA-Fe interaction potential has also been varied. Four effects are reported. First, the PKA mass has a major effect on cascade damage while the interaction potential has little if any. Second, the total number of point defects produced in a cascade decreases with increasing PKA mass. This fact is not accounted for in models used conventionally for estimating damage. Third, interstitial loops of �<111> type and both vacancy and interstitial loops of <100> type are formed, the latter being observed in MD simulation for the first time. The probability of <100> loop appearance increases with increasing PKA mass as well as energy. Finally, there is a correlation between production of large vacancy and interstitial clusters in the same cascade.
