Interferometric investigation of an early stage of plasma expansion with the high-power laser system PALS

Abstract

The results of interferometric investigation of early stage of plasma expansion carried out in the high-power laser system PALS are presented. The plasma was generated on planar solid Al and Mo targets, irradiated by iodine laser pulses with energies of 100 and 600 J in 0.4 ns at a wavelength of 1.315 µm. The interferometric investigation allowed to determine electron density distributions at chosen moments of the plasma expansion. On the basis of these distributions, information about dynamics and properties of expanding plasma was obtained. The effects of laser-target interaction, i.e., the diameter and the depth of craters as well as the crater shape, were investigated.