Transition from nonlocal electron transport to radiative regime in an expanding blast wave

We have investigated the formation, evolution, and late-time propagation of a laser-generated cylindrical blast wave (BW). The whole blast wave evolution over timescales of several nanoseconds was reconstructed experimentally (via temporally resolved interferometric measurements) and via hydrodynamic simulations that included modeling of nonlocal electron transport and radiation diffusion. Comparison between the experimental results and the simulations indicates that the early expansion phase is characterised by nonlocal electron heat transport causing energy spread on times shorter than the typical timescales for hydrodynamic expansion. Nonlocal electron transport ionizes the gas ahead of the plasma front and gives rise to a smooth radial density gradient. At later times, once the shock is launched and the BW is formed, radiation results in reduced shock velocity compared to the adiabatic case. These investigations provide a suitable and effective platform to benchmark the inclusion of kinetic and radiative effects in fluid modeling of the plasma dynamics over timescales that may be inaccessible to fully kinetic simulations.