Advanced railgun experimental test results and implications for the future

An advanced railgun has been designed, fabricated, and tested for the US Army. The railgun barrel is 7 m long and has a 90 mm (inner diameter) round bore. The barrel design incorporates unique features intended to contribute to improved railgun performance compared to more conventional designs. These features include very high bore stiffness and high bore prestress. These combined features minimize bore deflections and relative motion of bore mating parts, thus preventing plasma armature leakage and blow-by and enhancing performance. The high bore stiffness and prestress design features are gained through the application of advanced materials and engineering solutions. In particular, the use of high-modulus insulator materials, high strength-to-weight graphite/epoxy structures, and a high-pressure (20000 psi) hydraulic annulus allow for improved performance while permitting a substantial reduction (50-80%) in size and weight over more conventional approaches. Experimental test results and comparison with predicted results are presented