Two- and Three-Dimensional Analysis of Pulsed Power Instability Experiments

Hydrodynamic instabilities in fluids and plasmas are intrinsically nonlinear and three-dimensional, even if the bulk superstructure of an experiment is one- or two-dimensionally symmetric. Studying the emergence of three-dimensionality in such systems is important for understanding the appearance of disruptions and mixing in inertial confinement fusion ignition systems. The LANL/Sandia Z Double Cylinder platform is a multi-layer imploding system for examining the cumulative impact of interacting defects and shocks onto interior layers. An outer Be cylindrical liner is filled with liquid deuterium and imploded onto an interior Be cylinder and a center Cu rod. The nested cylinders are magnetically imploded with >20 MA of current, and perturbations are placed on the inner cylinder, driving a perturbed converging shock that disturbs the central rod and allows us to interrogate high-energy-density hydrodynamical processes. We compare two- and three-dimensional simulations of notionally two-dimensional cylindrically symmetric experiments, noting several differences in outcomes, including the appearance of Rayleigh-Taylor and Crow-like instabilities in 3D. Some, but not all, of these effects can be recovered in 2D using turbulence models.