Calculations and experiments of material removal and kinetic energy during pulsed laser ablation of metals

Numerical calculations are presented, which describe the processes of target heating and ablation of pure metals (for instance Fe) during irradiation by 30 ns laser pulses at 248 nm. The following effects are taken into account: the absorption of the laser radiation and the heat conduction within the target, the evaporation of material from the target surface, the cooling of the target surface by the heat of evaporation and the partial absorption of the incident laser beam in the evaporated material. As results of the calculations, the temperature profile in the target and the ablated material can be obtained. Furthermore, by energy balance, an energy of the ablated material of up to some 100 eV is obtained. Experiments performed concerning the threshold energy of ablation, the removed mass from the target and the kinetic energy of the deposited ions (by time-of-flight measurements) are in good agreement with the performed calculations.