Measurement of Radiation-Driven Shock-Induced Mixing from Nonlinear Initial Perturbations

Abstract

We present the first experimental measurement of the growth of a mixing region at a density interface from a high-amplitude, initially nonlinear perturbation. Thermal radiation from a gold Hohlraum irradiated by the Nova laser was used to drive a shock across a perturbed plastic-foam interface in a cylindrical shock tube attached to the Hohlraum. When the effects of target decompression are removed, the width of the mix region was found to grow logarithmically with time--- in agreement with recent theories for the nonlinear phase of the Richtmyer-Meshkov instability.