Investigating shock-driven Richtmyer-Meshkov Rayleigh-Taylor ripple evolution before and after re-shock*

Late-time Rayleigh-Taylor(RT)/Richtmyer-Meshkov(RM) instabilities in a planar geometry at high-energy-densities are investigated using a shock-tube containing a pre-machined interface between dense and light materials. The platform uses the NIF laser to indirectly drive a strong shock which turns the initially solid target into a plasma and the material boundary into a fluid interface with the imprinted initial condition. The interface evolves by action of the RT and RM instabilities, and the growth is imaged with backlit x-ray radiography. We present data from experiments using sinusoidal interface perturbations driven from the heavy to the light side. Late-time radiographic images show the initial conditions reaching the deeply nonlinear regime, and an evolution of fine structure consistent with a transition to turbulence. The evolution after re-shock, including a possible loss of initial conditions, and comparisons with post-shot numerical simulations are also discussed.