Theoretical modeling of the laser-solid-plasma interaction during UV laser ablation of metallic targets

A model of laser-solid-plasma interaction taking into account vapor ionization and absorption mechanisms and laser induced plasma kinetics was developed. The laser-solid interaction has been modeled by using a thermal approach, and inverse bremsstrahlung and direct photo-ionization from excited neutrals have been considered for the absorption of the laser light. The model shows that the plasma parameters, which are increasing function of the fluence at moderate laser intensities, approach a plateau regime at high laser fluences. Model previsions show a quite good agreement with the experimental findings suggesting that laser-plasma interaction processes and plasma kinetics are of great importance in nanosecond laser ablation of metallic targets for power densities of the order of similar to 10(9) Wcm(-2).