Transition conditions for solid armatures in railguns with muzzle current feed

The velocity skin effect is a principle reason that solid armatures in railguns transition from smooth metal-on-metal contact with the rails to arcing contact. Transition occurs when armature velocity reaches some critical value which depends weakly on current and strongly on the latent heat of evaporation and electrical conductivity of the armature material. Conductivity of the rail material is also a factor. The authors analysis shows that when current is fed to the armature from the muzzle of a railgun armature to the rail, current distribution is more uniform over the contact face than is the case with normal breech feed. They show that muzzle feed allows transition velocity to be increased three-fold.<>