A multiphase model for pulsed ns-laser ablation of copper in an ambient gas

Abstract

Laser ablation in an ambient gas is nowadays used in a growing number of applications, such as chemical analysis and pulsed laser deposition. Despite the many applications, the technique is still poorly understood. Therefore models describing the material evolution in time during short pulse laser irradiation can be helpful to unravel the puzzle and finally result in the optimization of the related applications. In the present work, a copper target is immersed in helium, initially set at atmospheric pressure and room temperature. Calculations are performed for a Gaussian-shaped laser pulse with a wavelength of 532 nm, full width at half maximum of 6 ns, and laser fluences up to 10 J/cm 2 .In order to describe the transient behaviour in and above the copper target, hydrodynamic equations are solved. An internal energy method accounting for pressure relaxation is applied for the description of the target. In the plume domain a set of conservation equations is solved,assuming local thermodynamic equilibrium. Calculated crater depths and transmission profiles are compared with experimental results and similar trends are found. Our calculations indicate that for the laser fluence regime under study, explosive boiling could play a fundamental role in the plasma formation of metals under ns-pulsed laser irradiation.

Lorenz Type Behaviors in the Dynamics of Laser Produced Plasma

“…This is a difficult task as the majority of the existent theoretical approaches focus on particular sequences of the laser ablation. Therefore, we found classical theoretical approach that focused on ultra-short laser interaction with dielectric material or metals [10], ns-laser ablation [11], thermal evaporation of material, particle ejection mechanisms and plasma formation or expansion. In the past decade there have been some proposals based on a fractal paradigm [12][13][14].…”

Laser-Induced-Plasma-Assisted Ablation and Metallization on C-Plane Single Crystal Sapphire (c-Al2O3)

“…The removal process happens as the overlapping of metal spots results in absorption of the laser beam by the previously deposited metal spot. At a low x , the deposition process dominates and more copper ions are deposited on the surface, and low resistivity can be achieved [ 21 ]. However, at a very high metal overlapping rate, the removal process dominates since the deposited metal absorbs the incoming laser pulse energy at the overlap zone, which causes laser ablation to remove the deposited materials.…”

Fluorescence imaging of ion distributions in an inductively coupled plasma with laser ablation sample introduction

“…The addition of He to the carrier gas significantly affects the ablation event, transport to the ICP, and conditions in the plasma [27,[41][42][43]. Helium could also change ion transport efficiency through the vacuum interface of the ICP-MS, although to our knowledge the effects of plasma gas composition on ion transport efficiency in the vacuum interface have not been studied.…”