Simulation and predicted performance of the Balcones GEDI experiment

The guided electromagnetic defense interceptor (GEDI) railgun launcher system is powered by six Balcones homopolar generators (BHPG), each of which stores 10 MJ in kinetic energy. Each BHPG is connected to a coaxial inductor which stores about half of the BHPG´s energy when charged to 1.2 MA. Six two-stage opening switches open in sequence or simultaneously after current peak, directing the current to the railgun armature. As much as 7.2 MA can be delivered to the railgun. A computer simulation code is developed to perform design parameter studies, sensitivity studies, and to predict GEDI system behaviors. The code is general enough for analyzing any railgun driven by multi-HPG inductors coupled with two-stage opening switches. A Gear type, multistep algorithm is used to overcome stiffness of the differential system caused by the way the switches are modeled. GEDI system performances are predicted with the code based on most updated component parameters.