Theoretical and numerical study of the interaction of a nanosecond laser pulse with a copper target for laser-induced breakdown spectroscopy applications

Abstract

International audienceThis work is a presentation of a modeling approach aimed at describing laser-matter interaction under laser-induced breakdown spectroscopy operating conditions. In order to set up a simple numerical tool to compute our model, only the most relevant processes appearing during the interaction were considered. This allowed us to develop a quick and rather accurate idea about how some physical parameters evolve during the interaction, so that the optimization of the laser beam parameters for better analytical results would be possible. For a basic understanding we used for our numerical computation a nanosecond laser pulse with an ideal Gaussian temporal profile and a pure Cu target. In order to optimize the interaction parameters, this study was focused on the effect of some of the laser parameters such as the wavelength (UV, Vis, IR), the pulse duration, and the irradiation on the results of the interaction. An investigation of the influence of some processes such as the vaporization effects and the plasma shielding was also included. The processes occuring on the material surface were closely examined as well. A comparison between the use of temperature-dependent and temperature-independent optical parameters was conducted, and their influence on the results was investigated. The use of variable optical parameters is revealed to be a means to correct the values of the temperature distribution inside the material and convert them into more realistic ones. Our code was first validated when operating under the same conditions used by other authors, and then it was used to present our proper contributions, as previously stated. (C) 2013 Optical Society of Americ

Extension of non-equilibrium modeling of metal ablation to the thermal effect inside the target material using a two temperature model

“…where is the reflectivity of the irradiated surface, and I 0 (t) is the incident laser intensity. The later is modeled by an ideal Gaussian temporal profile, [7][8][9][10][11]…”

“…In this paper UV nanosecond laser ablation of copper is investigated with a new upgraded model, consisting of a two temperature model coupled to a an out of equilibrium hydrodynamical one. Comparison with old studies using the same modeling approach under the hypothesis of thermal equilibrium inside the material [7][8][9][10][11] are presented.…”