A Study of Electrothermal Launcher Efficiencies and Gas Dynamics

Abstract

This paper describes a series of experiments to study the efficiency of an electrothermal (ET) launcher. The launcher serves as a pre-accelerator for a plasma-driven hypervelocity railgun experiment at the Institute for Advanced Technology. The ET launcher is designed to accelerate small polycarbonate projectiles to about 1 km/s. The objective of this study was to understand how pulse duration affects the efficiency with which the pressure of the ET discharge is coupled to the projectile. The study consisted of multiple tests for which the total energy of the discharge was kept constant, but the pulse length was varied. The dependent variable in the tests was the muzzle velocity of the projectile. The experimental results are presented and compared with gas-dynamic considerations.