EXPERIMENTAL INDICATION OF A BUFFER ZONE BETWEEN THE PLASMA ARMATURE OF AN EML AND THE PROJECTILE

The time-resolved light emission observed at 4000 A with a phototube, and at a fixed location along the bore, indicates that a warm, weakly ionized region may exist between the rear of the projectile and the armature. This observation supports the fact that the rear of the projectile shows very little ablation. We report here an attempt to observe this "buffer" region using a combined fiber optic probe and a conductivity probe located at the same bore position. The speed of the armature is obtained from interconnected B-probes, and the theory and use of this diagnostic is discussed.