Laser ablation and spallation of crystalline aluminum simulated by molecular dynamics

The mechanical action of femtosecond laser pulse on a target may result in ablation of the irradiated frontal layer and spallation of the target rear side as well. The dynamics of expansion of the solid Al film after laser heating is studied by means of molecular dynamics (MD) simulations with the two EAM potentials (ours and Mishin et al.) and our parallel auto-balancing MPD³ code. It is found that the rear side spallation threshold is half as much again the frontal ablation threshold. The experimental and evaluated characteristics agree well in both crater depth and incident fluence on the ablation threshold.