Experimental Results From a Two-Turn 40-mm Railgun

The Institute for Advanced Technology (IAT) has tested a high-inductance-gradient series-connected two-turn railgun. The primary goal of these experiments was to launch a dual-armature launch package in the two-turn configuration while maintaining electrical isolation between the rail and armature pairs. Two tests with the dual-armature launch package on a single-turn configuration independently examined the performance of the launch package. Results of those tests showed good thermal and structural performance of the armature assembly and no melt transfer between the armature contact regions. Five tests were then conducted on the two-turn rail configuration. During the second test, the crossover that connects the two rail pairs at the breech suffered arcing damage at the rail contacts. A new crossover was fabricated, and all subsequent tests were successful with no crossover arcing. The final system had a propulsive inductance gradient of 1.8
mu
H/m, with projectiles successfully launched in excess of 400 m/s at linear current densities up to 35 kA/mm.