Determining the electrical gradients of electromagnetic launchers using the transmission line model

A new technique has been developed for determining 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. This new technique was developed to replace the standard means of determining the gradients using fixed frequency AC measurements because the gradients are found to be frequency dependent. The approach extracts the gradients from experimental data obtained under actual firing conditions by solving the normal equations associated with the transmission line model. An experimental 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 actual operating conditions.