Optimization of the Performance of Cylindrical Hall Thrusters

Cylindrical Hall thrusters have lower surface-to-volume ratio than conventional (annular) design Hall thrusters and, thus, seem to be more promising for scaling down.\footnote{Y. Raitses and N.J. Fisch, \textit{Phys. Plasmas} \textbf{8}, 2579 (2001). }$^{,}$\footnote{Artem Smirnov, invited talk, this conference.} We present the results of the performance study of the cylindrical Hall thrusters with channel outer diameters of 2.6 cm and 3 cm. The effect of the magnetic field distribution and segmented electrodes on the thruster discharge characteristics and efficiency is investigated. The experimental results demonstrate a substantial flexibility in the thruster magnetic field configuration, which is a key tool in achieving the high-efficiency operation. The electron confinement and ion acceleration can be optimized over a family of realizable magnetic field distributions.