Spikes in condensed rare gases induced by keV-atom bombardment

We investigate by molecular-dynamics simulation the time evolution of a collision cascade in a condensed Ar solid, initiated by a 1-keV Ar atom. The particle density and velocity in the collision-cascade volume, the kinetic- and potential-energy distributions of the recoiling Ar atoms, and the energy distribution of sputtered particles are monitored. The high pressure building up in the core of the cascade drives the material into the cascade periphery and towards the surface. The surface erupts and hundreds of atoms are emitted, leaving behind a huge crater.