Rail and insulator erosion in rail guns

A persistent problem in rail guns is the erosion of rails and insulators, particularly near the breech. This is especially pronounced after multiple firings. Systematic experiments have been conducted using a 60 cm test bed facility designed for materials studies. Current waveforms characteristic of the early time for rail guns of 3-5 meters have been applied to the system using metal foil for the in-bore switch. The coupling of the resultant metallic plasma into the rail, the rail and insulator material removed, and the depth of rail surface melting have been determined as a function of position, local current density, and in-bore projectile speed.