Laboratory astrophysics experiments for simulation code validation: A case study

The growing field of Laboratory Astrophysics seeks to study the extreme environments found in many astrophysical events in the controlled setting of a laboratory. In addition to the opportunity to perform basic research into the nature and properties of materials in astrophysical environments, laboratory astrophysics experiments serve beautifully for validating calculations performed by simulation codes designed to model astrophysical phenomena. I present results from our ongoing validation effort for FLASH, a parallel adaptive-mesh hydrodynamics code for the compressible, reactive flows of astrophysical environments. The first test case is a laser-driven shock propagating though a multilayer target introducing Rayleigh-Taylor and Richtmyer-Meshkov fluid instabilities at the material interfaces. The second is an accelerating fluid interface that is subject to the Rayleigh-Taylor instability. We found good agreement between simulations and experiment for the multilayer target case, but disagreement between experiment and simulation in the Rayleigh-Taylor case. I discuss our findings and possible reasons for the disagreement.