Saturation of Laser Imprint on Ablatively Driven Plastic Targets

Abstract

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