Determining thermal power evolved in tungsten-barium cathode of Hall plasma thruster

Abstract

The operation of tungsten-barium cathodes for Hall plasma thrusters has been studied in a range of discharge currents within 1–5 A. Thermal power evolved in the cathode was evaluated in autonomous discharge tests and used to determine the cathode performance characteristics. It was established that the plasma temperature inside a cathode emitter is on a level of ∼2 eV, the cathode potential fall ranges within ∼9–12 V, and the ion current fraction amounts to Si ∼ 0.2. The actual current-voltage characteristic of the cathode in the Hall thruster significantly differs from that observed in the autonomous tests.