Residual plasma property control for hypervelocity railgun performance

The authors have been investigating alternative techniques for controlling the residual plasma left behind by the accelerating plasma armature. They believe that, if residual plasma resistance can be made sufficiently high, secondary currents will not occur. They describe residual plasma property control techniques which they have tested. Some of these lead to compact plasma armatures, without secondaries. Experimental data and analytical results showing the effect of these approaches are provided. At the velocities tested so far, one can prevent secondary formation by limiting or eliminating the plasma venting behind the main armature. Three different venting techniques have been successful at controlling plasma venting. The rail venting approach requires better seal design. The forward venting and insulator venting approaches require more test evaluation