BEHAVIOR OF MULTI-TIERED COPPER WIRE, SOLID ARMATURES

Several types of polycarbonate carriers have been designed to support multiple copper wires in a solid armature launch package. The carriers allow for the insertion of conductor mires at different axial locatio ns (tiers) in the launch package and provide initial contact loading b etween the wires and rails. This study began by investigating the poss ibility that armature electrical behavior could be obscured by conduct ive material in front of the primary current carrying elements. As the study progressed it became clear that more current was carried in the forward conductors than originally anticipated. This fact led to more detailed analytical and experimental investigations of insulator bodi es equipped with several tiers of conductor wires. A mathematical mode l of the multi-tiered armature was developed to assist in defining the electrical behavior. A variety of configurations of these launch pack ages have been tested in a 25 mm railgun powered by a laboratory capac itor bank. The packages maintained low voltage operation while incurri ng electrical actions that would have melted the conductor wires if al l of the current were confined in the rear most tier. The testing, mod eling, and analysis of voltage shielding and current sharing are prese nted along with the test results from several firings of the 25 mm rai lgun.