Reshocked Rayleigh-Taylor instabilities experiments on ORION

We report on Reshocked Rayleigh-Taylor Instability (RTI) experiments fielded on the ORION laser. These experiments build from a platform qualified on the LULI2000 facility which allowed to perform High Energy Density (HED) experiments in scaled conditions for Supernovae Remnants evolution [1]. A low density foam is used to trigger the RTI in deceleration, creating a well-developed mixing layer. The mixing zone width is diagnosed by x-ray point-projection radiography. On ORION, we benefit from the double-sided laser illumination to increase the level of mixing. The mixing zone is reshocked by a shock launched from the opposite side of the target. Re-shocking an already developed mixing zone is predicted to enhance the generation of turbulence, in shock tube or laser-driven experiments. We develop an HED analogue of RTI shock tube studies and study the influence of initial conditions on the mixing zone width evolution. Such highly nonlinear HED flows provide stringent benchmarks for radiation-magnetohydrodynamics code [2]. Our results will be compare against FLASH simulations and we will present the path forward to larger scale laser facilities.

[1] G. Rigon et al, Phys. Rev. E 104 (4), 045213 (2021).

[2] J.D. Bender et al, Journal of Fluid Mechanics 915 (2021).