In-bore armature contact voltage measurement

The authors have devised and tested a technique that allows the armature contact and bulk voltage to be measured during a railgun launch. The technique has been applied to both plasma and metal armatures. It requires no specialized equipment and can be easily applied to almost any launch package and railgun configuration. Preliminary results are given for both metal and plasma armatures launched from a square-bore railgun. It is concluded that the measurement technique is a useful tool for obtaining armature contact voltage during acceleration. Preliminary tests showed excellent results for metal armatures. Contact resistances were approximately 10 μΩ. Plasma armature results were not as promising. The data suggest that something unexpected happened to the measurement wires during and/or after plasma formation