Determining the Self-Similar Stage of the Rayleigh-Taylor Instability via LLNL's NIF Discovery Science Experiments

TL;DR

This paper presents a laser-driven experiment on the NIF to measure the self-similar growth constant of Rayleigh-Taylor instability, resolving previous discrepancies between experimental and simulation results.

Contribution

It introduces a novel experimental method to accurately measure RTI growth, aligning experimental data with 2D and 3D simulation predictions.

Findings

Measured self-similar growth constant $oldsymbol{}$=0.038±0.008

Results are consistent with 2D simulations

Results are closer to 3D simulation predictions

Abstract

We report a novel measurement of the late time self-similar growth constant $\alpha_B$ of the Rayleigh-Taylor instability (RTI) from controlled initial perturbations. To this end, we have developed a laser-driven experiment, fielded on the National Ignition Facility (NIF), to explore deeply non-linear, multimode hydrodynamic growth of a planar interface. The measured value is $\alpha_B=0.038\pm 0.008$, which is consistent with previously reported 2D simulations and closer to previously reported 3D simulations. This resolved the known discrepancy between experiments and simulations of RTI.