Behavior of fluid instabilities in laser fusion pellets: results of 2-D calculations

Two-dimensional Lagrangian hydrodynamics simulation techniques were used to study fluid instability in laser fusion pellets. A slab geometry comparison with classical Rayleigh-Taylor theory shows good agreement, as do other slab and spherical test problems over a wide range of accelerations and wavelengths. Isentropic ablative accelerations exhibit growth rates 50 percent-100 percent of classical values, while non-isentropic cases show suppressed growth. Design optimization at 100 kJ input energy has led to an impulsively accelerated, low- aspect-ratio shell which operates successfully with a surface perturbation of a few tens of angstroms. Comparison of simulations with present experiments indicates that current neutron-producing targets are insensitive to damage from fluid instability. (auth