A 3D Model of Directly-Driven Cylindrical Implosions for Bayesian Analysis*

Directly-driven cylindrical implosion experiments conducted at the Omega Laser Facility are used to study the effects of converging hydrodynamic instabilities in the high energy density (HED) regime. A sinusoidal perturbation seeded along a cylindrical tracer shell results in instability growth driven by a combination of Rayleigh-Taylor, Richtmyer-Meshkov, and Bell-Plesset effects. By imaging down the axis of the cylinder and radially from the side simultaneously, we obtain crucial information as to how these systems decelerate, stagnate, and evolve. Proper understanding of these instabilities at HED conditions can inform the design of platforms like the Los Alamos Double Shell program [1,2]. We are developing a tool to generate synthetic radiographs of a parameterized 3D model of the driven cylinder, which are compared against the data. A parameter space is found via Bayesian inference and Markov Chain Monte Carlo (MCMC) methods [3,4], providing statistical metrics on features in the data. These results can then be used to inform both hydrodynamic simulations as well as experimental design.

[1] P. Amendt et al. PoP 9 (5): 2221–2233 (2002)

[2] D. S. Montgomery et al. PoP 25 (9): 092706

[3] P. F. Knapp and W. E. Lewis. RSI 94 061103 (2023)

[4] M. F. Kasim et al. PoP 26 (11): 112706 (2019)