Unstable Discharge Phenomenon and Stabilization of Hall Thruster Operating in Self-Excited Mode

摘要

An unstable discharge phenomenon is observed in a 1 kW Hall thruster operating with the electromagnets driven in series by the discharge current. The discharge current jumps between two current levels. Performance is measured at discharge currents of 3.9 and 4.7 A. Measurements indicate the performance at 4.7 A is found to be lower. The instability corresponds to operation of the Hall thruster over a narrow range of the anode mass flow rate. Outside that range, the current is stable at other values and remains almost linearly proportional to the mass flow rate over a wide range. To better understand this unstable discharge phenomenon, the stability of the thruster at operating points where the magnetoampere characteristic curve intersects the magnetic field coil current curve are analyzed. A proposed method for stabilizing the discharge current is then validated through experiments.