A study of electric discharge phenomena initiated by plasma from electric thrusters in electric circuits of high-voltage solar arrays

The paper presents results of experimental studies into mechanisms generating electric discharge phenomena, which may occur in electric circuits of high-voltage solar arrays (SA) of spacecraft equipped with electric thrusters. The paper was occasioned by the need to protect high-voltage SA of spacecraft against destructive effects of discharges initiated by plasma from electric thrusters. The paper demonstrates that depending on the voltage and exposed area of the SA electrodes, their potential with respect to potential of the plasma generated by electric thrusters may have both positive and negative values comparable with the SA operating voltage. It demonstrates that on positively charged electrodes there can be powerful arc discharges accompanied by strong heating up of electrodes and their adjoining dielectrics. But even in the cases where the discharges do not occur, there are always leak currents through plasma, which reduce the SA output power. On the negatively charged electrodes in the plasma from electric thrusters, micro-arc discharges can often occur, which, under certain conditions, may develop into an arc discharge.