Hydrodynamic simulations of perturbed shock propagation with viscosity*

There are limited experimental methods available to probe viscosity of materials at high-energy-density conditions; one such method tracks the evolution of a rippled shock front. Here, we conduct a study of the effect of viscosity on the propagation of a perturbed shock using the radiation-hydrodynamics code FLASH. To facilitate comparison with our experiments, we apply a laser driver to dynamically compress a fused silica target to ~300 GPa, where the target has a 200 um-wavelength sinusoidal interface. By varying the dynamic viscosity, we anticipate differences in the decay and oscillation of the perturbed shock front over time. Moreover, using the simulation output, we can generate synthetic VISAR and streaked optical pyrometry (SOP) data typically obtained during experiments. With the synthetic data, we can better understand the range of viscosities that can be resolved experimentally and constrain future experimental design.