Determining the Time Dependence of Electrical Gradients in Railguns Using the Transmission Line Model

A new technique has been developed for determining the time dependence of the inductance and resistance gradients of electromagnetic launchers. These are fundamental parameters when estimating launcher performance. The method is based on our analysis that shows how a transmission line model describes the relationship between the voltage gradient along the launcher rails and the rate of change of current. The approach extracts the gradients from experimental data by solving the normal equations associated with the transmission line model. An electromagnetic launcher was developed to test this new approach and experimental results are in excellent agreement with predicted behavior. This new technique provides a straightforward means to accurately determine the gradients of experimental designs under dynamic conditions. The data for these gradients are new and not available by any other known technique.