Modelling of Plasma Temperatures and Densities in Laser Ablation Plumes of Different Metals

Abstract

Laser ablation has many uses in industry, including laser drilling and thin-film deposition. However, the underpinning physics of laser ablation has not been fully elucidated. In particular, the differences in the behaviour of plasma plumes ablated from different materials, and which material properties are related to plume characteristics, require further study. This paper presents results from modelling the laser ablation of different photocatalytic materials using the 2D hydrodynamic laser ablation code POLLUX. The evolution of key parameters such as plasma density and temperature is investigated when the target material is changed from titanium to tantalum, zinc, copper, aluminium and gold. It was found that the atomic number of the material significantly affected the electron temperature and mass density of the subsequent plasma plume, with both parameters increasing with atomic number, whilst other parameters including the mass density, thermal conductivity and melting temperature did not affect the electron temperature or particle density of the plumes. These results provide insights for future laser ablation experiments where the aim is to change the target material, but keep the plume parameters as constant as possible.