Diagnostics of plasma plume produced by laser ablation using ICCD imaging and transient electrical probe technique

Abstract

The dynamics of transient plasmas generated by high-fluence nanosecond laser ablation has been investigated by means of fast ICCD imaging and electrical probes in transient regime. Measurements have been carried out on plasmas produced in vacuum (5× 10−6 Torr residual pressure) by a pulsed Excimer laser (20 ns, XeCl, λ= 308 nm) irradiating stainless steel targets. Two plasma expansion velocities were estimated, one from probe measurements and another from recorded ICCD images. Electron plasma temperature (0.1 − 0.3 eV) and density (1 − 5×1011 cm−3) were measured by electrical probes for a laser radiation power density of 6×108 W/cm2.