Study of radiative shocks using 2D interferometry and XUV spectroscopy

Abstract

We report new experimental results on radiative shocks obtained in Xenon and Argon in gas cells at two different pressures below 1 bar. These shock waves are generated by the interaction of the PALS iodine laser on a CH-Au foil with a typical velocity in the range of 50-100 km/s depending on the variable laser intensity, pressure, and gas. Attention is paid to the morphology and the dynamics of the radiative precursor over large time scales up to 30 ns, using 2D sub-picosecond visible interferometry, illustrating the complex interplay of hydrodynamic and radiation absorption for different initial conditions. The comparison between 1D and 2D simulations confirms the role played by lateral radiative losses in the ionization wave and the necessity of state-of-the-art integrated opacities. This study is complemented by the first XUV analysis of the shock emission between 5 and 20 nm obtained with a grating spectrometer, with line identification, which is compatible with the ionization stages deduced from interferometry and simulations.