Hydrodynamic modeling of laser interaction with micro-structured targets

A model is developed for numerical simulations of laser absorption in plasmas made of porous materials, with particular interest in low-density foams. Laser absorption is treated on two spatial scales simultaneously. At the microscale, the expansion of a thin solid pore wall is modeled in one dimension and the information obtained is used in the macroscale fluid simulations for the description of the plasma homogenization behind the ionization front. This two-scale laser absorption model is implemented in the arbitrary Lagrangian–Eulerian hydrocode PALE. The numerical simulations of laser penetration into low-density foams compare favorably with published experimental data.