Theoretical studies on non-linear stages of hydrodynamic instability in laser driven implosion

Three topics related to the non-linear stages of hydrodynamic instability in laser driven implosion are studied: (1) With the help of a two dimensional Lagrangian hydrocode, the generation of a turbulence state through mode-mode coupling in the Rayleigh-Taylor instability has been demonstrated. (2) Anomalous energy diffusion due to turbulence is described by a non-linear diffusion model, explaining the degradation of neutron yield in a high density implosion experiment. (3) Fundamental studies have been performed theoretically and numerically on linear and non-linear stages of the Richtmyer-Meshkov instability to obtain and confirm a universal relation describing its evolution. (author). 9 refs, 4 figs