Improving analytical models of Rayleigh-Taylor instability within plasmas*

The linear Rayleigh-Taylor (R-T) instability with transport effects has long been studied analytically in the neutral fluid regime. However, the ways in which this picture may differ in plasmas has been given less consideration. By leveraging previous (plasma transport effect incorporating) numerical simulations of R-T at binary plasma interfaces, we show how multi-ion plasma diffusion, viscosity, and ion kinetic effects alter the linear R-T dispersion relation. Our insights inform an improved analytical dispersion relation for plasmas, which better matches the simulation data than previously established models. Additionally, we demonstrate that accurately capturing plasma R-T growth within fluid simulations requires employing asymptotically-correct viscosity coefficients.