Current carrying capacity of solid armatures for railguns at zero speed

Abstract

A very large body of work exists which describes the design, construction, and performance of railgun armatures when they are accelerated in real railguns. Much less is known about how armature-type assemblies behave when forward motion is prevented. We suggest that valuable armature data might be obtained by doing experiments at zero velocity. In this program we have confirmed yet again that divided contacts carry high currents more reliably than do monolithic contacts, We have also shown that for these multipoint armature contacts, when the force holding the contacts onto the rail is around one gram force per amp and this minimum force is maintained for the whole duration of the pulse, contact transition does not occur. This work suggests that the contact transitions which commonly occur as current is falling, towards the end of a pulse, are caused by loss of adequate contact force.