Effect of laser parameters on laser ablation and laser-induced plasma formation: A numerical modeling investigation

A comprehensive numerical model has recently been developed for nanosecond (ns) laser ablation of metallic targets, describing the processes of target heating, melting and vaporization, the resulting plume expansion in I arm helium gas, as well as plasma formation in the plume. In the present paper, we investigate the influence of laser parameters, i.e., laser irradiance, pulse duration and wavelength, on typical calculation results, such as the target temperature, melt and evaporation characteristics, the plume expansion velocity, plume (plasma) temperature and ionization degree, densities of neutrals, ions and electrons in the plume, as well as the laser absorption characteristics in the plume (plasma shielding). Comparison is made with experimental data from literature, whenever available, and in general, good agreement is reached between our model predictions and experimental results. Therefore, the model can be useful to predict trends in target and plume (plasma) characteristics, which are difficult to obtain experimentally. (c) 2005 Elsevier B.V. All rights reserved.