Rail guns driven by helical flux compression generators

Explosively-driven helical flux compression generators are generally of larger inductance and therefore of higher energy gain than most other flux compression generators. On the other hand the operation times (usually 200 to 300 ..mu..s or less) are usually too short to serve as direct power supplies for most rail gun applications. This limitation is circumvented, however, when the generator is used to charge an inductive storage coil, which then serves as the rail-gun energy source. We describe here the results of several recent tests with such systems. Projectile masses have ranged from 0.6 to 1.0 kg; both plasma and solid armature modes have been employed. The flux compression generator and its characteristics are describeed, together with the storage coil, the rail gun, projectiles and diagnostics employed. Particular attention is devoted to minimizing flux losses, for example, in the design of the storage coil input crowbar which is activated after the coil is loaded by the generator.