Spectroscopic measurements of railgun plasma armatures in an augmented railgun using a permanent magnet

Measurements of electron density using Stark broadening of the H/sub /spl alpha// line are performed to investigate the behavior of plasma armatures in rail guns with and without an augmenting magnetic field. A permanent magnet with a magnetic flux density of 1.25 T was used to augment the magnetic field of one railgun. Driving currents of 20 and 25 kA are supplied to the railguns with and without the augmenting magnetic field, respectively, in order to maintain the same peak Lorentz force on the projectile. Also a gradual temporal increase in electron density and length of the plasma armature is observed in the augmented railgun.