MD simulation of surface smoothing due to cluster impact: estimation of radiation damage

The radiation damage of irradiated surfaces by cluster ion with a few eV/atom is studied through molecular dynamics simulations, where (Ar)3055 clusters with 3-10 eV/atom are bombarded on a rough Cu surface. Since energetic primary knock-on atoms are not created by the big cluster bombardment with a few eV/atom, the Frenkel pair is not observed. However, we found some vacancy, dislocation and stacking fault beneath the irradiated surface. These defects are generated by the plastic deformation and the melting of the surface, because the big cluster impact produces very high particle and energy densities in a small impact region.