A SIMPLE MODEL FOR THE MOTION OF PULSED-LASER-DRIVEN THIN FLYERS

Abstract

Abstract - A model that predicts the final velocity of high-power, pulsed-laser- driven thin flyers is described. The required input parameters can either be obtained from standard handbooks or simply extracted from one set of data. The model yields a number of features and scaling laws that are well verified by experiment. Specific comparisons of model predictions with experimental results illustrate excellent agreement for variations of laser fluence and pulse width as well as flyer diameter and thickness. Introduction Previous work 111 has shown that simple models can be used to describe the recoil momentum generated by the explosive vaporization caused by high-power pulsed radiation loads incident on target surfaces (e.g., from lasers). In most earlier investigations the vaporized blowoff products were allowed to expand freely. In the present study, short high-intensity laser pulses are transmitted through fused silica optical fibers onto thin-foil metallic flyers placed on the fiber ends. In this case the blowoff reactions are fully tamped by the fiber, and free expansion does not occur. The configuration is shown schematically in Figure 1. To describe this situation, we have developed a simple model, employing conservation of energy and momentum, in the framework of the well-known Gurney theory for high-explosive-driven plates [2,