Using CRASH to analyze experimental setups in Kevin-Helmholtz experiments*

Recent series of experimental shots explored the importance of the Kevin-Helmholtz instability in early galactic formation, specifically cold, dense streams feeding mass into a galaxy. The experiment basic setup was a laser-driven shock in low-density foam over a perturbed solid rod. However, subsequent experimental shots showed differences in shock speeds which required investigation. These results are explained by changes in diagnostics and laser drive. We used the radiation hydrodynamics code CRASH supplemented by Leeor one dimensional code simulations to explain the differences in shock speeds. These simulations provided a key role for analysis for how variations in experimental setup resulted in the shock speed differences.