The dynamic properties of shock-waves formed during laser ablation at sub-atmospheric pressures

Abstract

The Sedov-Taylor-von Neumann (STN) theory has been shown to accurately describe the dynamic properties of shock-waves generated during pulsed-laser ablation of solid aluminium targets at visible wavelengths (510/578 nm) with 40 ns pulses with energies up to 3.5 mJ. A ballistic pendulum is used to measure the integrated recoil pressure in various inert atmospheres (He, Ne, Ar, Kr, Xe, N2, CO2, SF6) with pressures of 10−2 − 103 mbar. This recoil momentum is found to scale linearly with the background gas pressure P1 and with the square root of the molecular weight M1. More interestingly, the scaling with the ratio of heat capacities γ is verified to be a monotonically increasing function dependent on the form factor of the shock-wave. The validity of a modified STN theory which accounts for the piston mass is assessed.

Dynamic Structure and Mass Penetration of Shock Wave in Picosecond Laser-Material Interaction

“…Zhang and Gogos 12) developed a theoretical model to describe the laser ablation in a background gas under the effects of laser intensity and background gas. Kapitan and Coutts 13) investigated the dynamic properties of shock waves generated during pulsedlaser ablation of solid aluminum targets at sub-atmospheric pressure by using the Sedov-Taylor-von Neumann theory.…”