A study of current distribution in electromagnetic launcher rails

The transient capability of the Westinghouse Electric and Magnetic Field Analysis Program, WEMAP is applied to the design of rails used in electromagnetic launchers. The manner in which current penetrates the rails is studied. Regions of high current density are identified, and the influence of cladding and chamfering on the current densities is examined. The instantaneous force densities, resistance, and inductance are presented as a function of time for a typical current pulse and rail geometry. It is shown that cladding the rails has little effect on the current and flux distributions in the copper beyond slightly reducing the copper area. Chamfering the inner rail corners reduces the peak current density by about 20% in the example here, which amounts to a 36% reduction in the peak losses which occur at the inside corners