Oscillatory current generation in a Hall accelerator

The operation of a Hall accelerator was studied in the Potok apparatus. When the supply voltage is raised above a certain critical value, the steady state operation of the accelerator which is characterized by small perturbations of the discharge current and anode voltage gives way to a regime in which powerful current pulses occur periodically with practically no current between pulses, i.e., to a spontaneous oscillation of the current in the accelerator. The duration and height of the current pulses increase by a factor of less than three as the circuit inductance is increased from 0.1 to 470 microH. In order to determine the mechanism for the observed oscillations, the space and time distributions of the emission from the plasma in the accelerator channel and its vicinity were studied.