Laser-Induced Plasma on a Titanium Target, a Non-equilibrium Model

Abstract

International audienceWe use a comprehensive model to investigate the interaction of ultraviolet nanosecond laser pulses with a titanium material. We calculate plasma ignition thresholds and study the effect of the laser-plasma interaction and the importance of the electronic non-equilibrium in the laser-induced plume and its expansion in the background gas. Our calculations of plasma ignition thresholds on titanium targets are validated and compared with experimental and theoretical results. A comparison with experimental data indicates that our results agree well with those reported in the literature. Results for titanium and copper are also compared under the same conditions. The inclusion of electronic non-equilibrium in our work indicates that this important process must be included in laser ablation and plasma plume formation models

Dynamics of UV short pulse laser-induced plasmas from a ceramic material “titanium carbide”: a hydrodynamical out of equilibrium investigation

“…For that reason, nanosecond laser pulses interaction with titanium carbide can be described through a one temperature thermal model (Ait Oumeziane and Parisse, 2018). At the course of our research development (Ait Oumeziane et al, 2016a, Ait Oumeziane and Parisse, 2018, Ait Oumeziane et al, 2014, Ait Oumeziane et al, 2016b we have always chosen to adopt an enthalpic formulation of the heat equation (1), which greatly facilitates the phase changes (solid/liquid, liquid/vapor) management. In addition, thermophysical and optical properties were always assumed only phase dependent.…”

“…A one-dimensional (1D) description of the laser beam interaction with the target material is suitable because the thermal diffusion length of titanium carbide under the present conditions is largely greater than the laser beam penetration depth. In addition, the standard excimer beam radii and the assumed material thickness enable us to neglect the lateral diffusion flux and consider the space-time computational domain large enough to assume its outer boundary unaffected by the laser pulse absorption and heat diffusion (Ait Oumeziane et al, 2016a). At the target surface, a zero-heat flux boundary condition is assumed up to the time the surface starts to evaporate.…”

“…The coupling of the thermal and hydrodynamical solvers allow to have a general and accurate overview of the entire ablation process. Because this code has already been used effectively to simulated laser ablation of semiconductors (Parisse et al 2011) and metals (Ait Oumeziane et al 2016a, Ait Oumeziane et al 2014, Ait Oumeziane et al 2016 we know that it is adapted to such multiphysics problems.…”

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.…”