The Stabilizing Effect of a Magnetic Field on the Plasma Production of a Vacuum-Discharge Rotating Plasma Gun

Abstract

A coaxial plasma gun which generates a rapidly rotating plasma in a magnetic field has been developed to improve the plasma centrifuge. It is demonstrated that a magnetic field stronger than a critical value is essential to stabilize the high-current vacuum discharge of the plasma gun and to make the plasma production and acceleration reproducible. For example, the critical field is 250G for the discharge current of 13kA and the anode-cathode spacing of 7.5mm. A model is presented in which the critical field is assumed to be determined from the trapping of ionizing electrons in the annular anode-cathode gap. A qualitative agreement is achieved between the model and experiment.