Fluctuation-induced transport in the Hall plasma accelerator

This paper considers small-amplitude fluctuations in the Hall-effect thruster. To predict which fluctuations could be important to transport, the growth of a disturbance is determined as a function of real frequency and propagation angle. In the simple case, strong growth is predicted for disturbances that are azimuthal. In the general case, strong growth is predicted for various propagation angles. To determine if these modes could explain the mobility, the phase separating fluctuations in the velocity and number density is estimated. Significant transport is predicted for disturbances in certain frequency/wavenumber regimes. As a consequence, it is concluded that small-amplitude fluctuations could explain the transport in the Hall-effect thruster, and that spatial variation in the oscillation spectra could account for position dependent electron mobility.