Laser-produced post-pulse crater formation in solids observed in PALS facility interaction experiment

Results from PALS facility laser-massive Al target interaction experiments are reported. Main attention is devoted craters formation under the action of laser pulses of various energy (from 100 J up to 600 J), intensity (from 1013 W/cm2 up to 1015 W/cm2), laser wavelength (0.438 μm and 1.315 μm), and focal beam radius (from 35 μm up to 600 μm). Crater replicas were made of wax and their depths and radii were subsequently obtained by microscopy measurements. Duration of the laser-pulse-initiated shock wave propagation into the targets was much longer than that of the laser pulse itself (400 ps). This was an important feature of the experimental arrangement. Theoretical model of the post-pulse crater formation by the shock wave propagating and decaying in solids after the end of the laser pulse is presented and applied for explanation of the results obtained in experiments.