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 ir radiation by 30 ns laser pulses at 248 nm. The following effects are t aken into account: the absorption of the laser radiation and the heat conduction within the target, the evaporation of material from the tar get surface, the cooling of the target surface by the heat of evaporat ion and the partial absorption of the incident laser beam in the evapo rated material. As results of the calculations, the temperature profil e in the target and the ablated material can be obtained. Furthermore, by energy balance, an energy of the ablated material of up to some 10 0 eV is obtained. Experiments performed concerning the threshold energ y of ablation, the removed mass from the target and the kinetic energy of the deposited ions (by time-of-flight measurements) are in good ag reement with the performed calculations.