Electron Motion in a Stationary Plasma Thruster

Electron motion in a classical three-block model of the stationary plasma thruster (SPT) invented by A.I. Morozov is analyzed. It is demonstrated that the motion of electrons produced with a zero initial velocity due to working gas ionization critically depends on the position of the starting point along the accelerating channel axis. While the electron trajectories in the cathode region are regular, they become ergodic closer to the anode, which is accompanied by enhanced particle transport along the thruster channel. This transition is associated with the presence of a boundary at which erosion of the discharge chamber wall takes place in the experiment. The discovered ergodization of electron trajectories can be responsible for the anomalous electron conductivity in the near-anode region of the SPT.