SATURATION OF LASER IMPRINT ON ABLATIVELY DRIVEN PLASTIC TARGETS

The imprinting of areal density perturbations on thick planar plastic targets has been studied numerically and analytically. Simulations pre dict that the target modulation saturates while still in a small-ampli tude regime. General scaling laws relating saturation times and amplit udes to mean laser drive and wavelength, and perturbation amplitude an d wavelength, are summarized from the simulations. A linear gasdynamic model is used to study the physical mechanisms responsible for the sa turation, and provides strong evidence that mass ablation is the domin ant stabilizing influence.