Analysis of a railgun capacitor-muzzle-shunt energy recovery scheme

A large fraction of the energy initially stored in a railgun pulsed power system normally remains in the circuit when the projectile exits. This residual energy, much of it stored in the barrel inductance, can be close to 50% of the initially stored energy. This is the result of significant current flowing in the projectile armature when the projectile exits the barrel. Muzzle shunts are designed to manage this residual current and energy, and as a result reduce or eliminate muzzle flash. To date, resistive and inductive muzzle shunts have been proposed and implemented. Resistive shunts can dissipate a majority of the residual energy in addition to preventing muzzle flash. Inductive-shunt schemes have been proposed as a means to recover the residual energy in a pulsed-alternator pulsed-power system. This paper describes a different muzzle-shunt approach; a capacitor shunt that is used to recover a large portion of the residual energy. This muzzle shunt is used in conjunction with a capacitor-based pulsed-power system, where one of the capacitor bank sections is used both as the shunt element as well as the recovered-energy storage element. Results are presented of an analysis of this scheme using a transient circuit model of a representative railgun circuit.