Bistable phenomenon of discharge in a Hall plasma accelerator

An interesting phenomenon is observed in a 1 kW Hall plasma accelerator operating with the electromagnetic coils in series with the discharge circuit. The discharge current jumps to-and-fro between two different values. This phenomenon is named bistable characteristic of discharge current of a Hall plasma accelerator in this paper. As a whole, the discharge current has no obvious regular period, the frequency of discharge current hopping is much less than that of typical low frequency plasma oscillation. The physical mechanism of this phenomenon is analyzed through the magneto-ampere curve. A steady method of discharge current is presented and demonstrated through experiments.