Quasi-steady state, low current performance of a coaxial plasma source experiment

Abstract

Summary form only given. The coaxial plasma source-I (CPS-1) facility at N. C. State University was recently upgraded to enhance the performance of the pulse-forming network (PFN). This upgrade provides a peak gun current of 22 kA with 1. 1 ms pulse length at a gun voltage of 50 V, for an initial 3 kV charge on the PFN. CPS- I can be operated in either unmagnetized or magnetized flow. When unmagnetized, only the plasma's self-magnetic field serves to accelerate the plasma in the gun channel. In the magnetized flow an external applied field serves to nozzle the plasma flow outside the gun channel. The magnitude and duration of the current pulse is not affected by the applied magnetic field. Furthermore, the voltage across the gun channel remains constant at 50 V through out the duration of the pulse independent o the initial charge on the PFN, and therefore the gun resistance decreases with increased gun current. The gun resistance is 2.5 m:Q for a 3 kV charge on the PFN, and drops to 1.4 m/spl Omega/ when the gun current peaks at 35 kA, for a 5 kV charge on the PFN.