Studies in the nonlinear evolution of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities and their role in inertial confinement fusion

Hydrodynamic instabilities, such as the Rayleigh-Taylor and Richtmyer-Meshk ov instabilities, play a-central role when trying to achieve net thermonucl ear fusion energy via the method of inertial confinement fusion (ICF). The development of hydrodynamic instabilities on both sides of the compressed s hell may cause shell breakup and ignition failure. A newly developed statis tical mechanics model describing the evolution of the turbulent mixing zone from an initial random perturbation is presented. The model will be shown to compare very well both with full numerical simulations and with experime nts, performed using high power laser systems, and using shock tubes. Apply ing the model to typical:ICF implosion conditions, an estimation: of the ma ximum allowed target, in-flight aspect ratio asa function of equivalent sur face roughness, will be derived.