Electron Cross-Field Transport in a Miniaturized Cylindrical Hall Thruster.

Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. The present paper gives a review of the experimental and numerical investigations of electron cross-field transport in the 2.6-cm miniaturized cylindrical Hall thruster (100-W power level). We show that, in order to explain the discharge current observed for the typical operating conditions, the electron anomalous collision frequency vB has to be on the order of the Bohm value, vB ≈ wC/16. The contribution of electron-wall collisions to cross-field transport is found to be insignificant. The optimal regimes of thruster operation at low background pressure (below 10-5 torr) in the vacuum tank appear to be different from those at higher pressure (∼ 10-4 torr). [ABSTRACT FROM AUTHOR]