Experimental Insights Into High-Frequency Instabilities and Related Anomalous Electron Transport in Hall Thrusters

The properties of high-frequency (HF) instabilities (f > MHz) in Hall thrusters are reviewed on the basis of a large experimental data set previously obtained with the use of antennas, probes, and magnetic coils. The phenomenological representations of their physical sources are discussed. The development of these HF instabilities results in anomalous electron transport, and the corresponding transport coefficients are evaluated from these experimental data.