Time-resolved measurements of laser-induced shock waves in deuterated polystyrene porous targets by x-ray backlighting

Experimental studies are presented of laser-driven shock waves in deuterated polystyrene porous targets observed with x-ray streak shadowgraphy. Using two different target-mass densities of 0.1 g/cm3 and 0.2 g/cm3, the density dependence of the shock velocity was obtained as vs∝ρ-0.45±0.02 and agreed well with a simple scaling obtained from the Hugoniot relation. X-ray shadowgraphy has shown a shock formation in porous targets and analysis suggests that there are two parts to compression waves: a shock front and a following pileup zone of multiple shock waves. Temporal histories of the pressure, the temperature, and the compression were estimated from the measured shock velocities and the opacities. It was found that the pressure peak due to the shock front was retarded to that by the pileup zone. The pileup zone had a higher compression and followed a thermodynamic condition closer to an adiabat than the shock front