Three-dimensional numerical investigation of electron transport with rotating spoke in a cylindrical anode layer Hall plasma accelerator

Abstract

The effects of increased magnetic field and pressure on electron transport with a rotating spoke in a cylindrical anode layer Hall plasma accelerator are investigated by three-dimensional particle-in-cell numerical simulation. The azimuthal rotation of electron transport with the spoke has a frequency of 12.5 MHz. It propagates in the direction of the E × B drift at a speed of ∼1.0 × 106 m/s (about 37% of the E × B drift speed). Local charge separation occurs because the azimuthal local electron density concentration is accompanied by an almost uniform azimuthal ion distribution. The non-axisymmetrical electron density concentration and axisymmetrical ion distribution introduce two azimuthal electric fields with opposite directions in the plasma discharge region. The axial electron shear flow is excited under the additional Eθ × B field. The anomalous electron transport with the rotating spoke may be attributed to the axial electron shear flow induced by the two azimuthal electric fields with opposite directions as a result of the azimuthal local electron density concentration.