We report on the design and first results from experiments looking at the formation of radiative shocks on the Shenguang-II (SG-II) laser at the Shanghai Institute of Optics and Fine Mechanics in China. Laser-heating of a two-layer CH/CH–Br foil drives a $\sim 40$ km/s shock inside a gas cell filled with argon at an initial pressure of 1 bar. The use of gas-cell targets with large (several millimetres) lateral and axial extent allows the shock to propagate freely without any wall interactions, and permits a large field of view to image single and colliding counter-propagating shocks with time-resolved, point-projection X-ray backlighting ($\sim 20$ μm source size, 4.3 keV photon energy). Single shocks were imaged up to 100 ns after the onset of the laser drive, allowing to probe the growth of spatial nonuniformities in the shock apex. These results are compared with experiments looking at counter-propagating shocks, showing a symmetric drive that leads to a collision and stagnation from $\sim 40$ ns onward. We present a preliminary comparison with numerical simulations with the radiation hydrodynamics code ARWEN, which provides expected plasma parameters for the design of future experiments in this facility.

We analyze the results of a recent experiment performed at the PALS laboratory and concerning ablation pressure at 0.44 µm laser wavelength measured at irradiance up to 2 × 1014 W/cm2. Using the code “ATLANT,” we have performed two-dimensional (2D) hydrodynamics simulations. Results show that 2D effects did not affect the experiment and also give evidence of the phenomenon of delocalized absorption of laser light.