Interpreting shock release studies of compounds using a forward VISAR model of molecular dynamics simulation

Shock release or rarefaction is the process of material tear-out that occurs when a shock exits a solid material into a low-density or vacuum region. The amount of mass and the speed of the material released have been studied for several years since this phenomenon sets the initial conditions for an inertial confinement fusion implosion. It has been shown that rarefaction from CH plastics separates into C and H portions, and that this separation is adequately predicted by classical molecular dynamics (CMD) simulations. The authors present a further study of species separation using CH, CD, pure C, and SiO₂ samples to test CMD predictions. The time of flight between the leading, low-density, lighter species portion of the release and the denser, heavier species portion agree well with CMD predictions. The density profile of the CMD model’s prediction can be inferred by convolving the simulation with a forward model of VISAR and comparing to the raw experimental data. This material is based upon work supported by the Department of Energy [National Nuclear Security Administration] University of Rochester “National Inertial Confinement Fusion Program” under Award Number DE-NA0004144 and Department of Energy, Office of Science under Award Number DE-SC0024456.