Numerical investigation of influence of finite sample thickness on laser ablation of materials

We offer to your attention a preprint “Numerical Solution of the Cauchy Problem Based on the Basic Element Method” (P11-2022-32) published by the JINR Publishing Department. The authors: I. V. Amirkhanov, I. Sarkhadov, Z. K. Tukhliev, H. Gafurov.

In previous works, numerical simulations of laser ablation of materials that occurs under the action of ultrashort laser pulses in semi-constrained samples were carried out. In the present work, a similar numerical study was carried out in samples of a finite size. The action of the laser is taken into account through the source functions in the heat conduction equation, setting the coordinate and time dependences of the laser source. During laser ablation of the material, the thickness of the sample changes. By passing to the moving coordinate system, the problem with moving boundaries is transferred to the problem with fixed boundaries. In this case, in the heat conduction equation, along with the diffusion term, a convective heat transfer term arises. In our new formulation of the problem, the variable thickness of the sample affects not only the convective term, but it affects the diffusion term, the source functions, and the boundary conditions of the heat equation. These influences are visible from the mathematical formulation of the problem itself.