Hall accelerator with preionization discharge

Claim 1

A Hall accelerator with preionization discharge, comprising a main discharge area having an anode means and a cathode means coupled to opposite ends thereof respectively; said anode means having concentric cylindrical electrodes coaxial with said main discharge area, an anode terminal means adapted to apply a voltage across the concentric electrodes to generate an electric field therebetween, and an auxiliary electromagnet surrounding said concentric electrodes so as to generate a magnetic field in a longitudinal axial direction of the concentric electrodes, so that said anode means forms a magnetron type preionization discharge area in communication with said main discharge area; said cathode means having an inner semispherical electrode aligned with said main discharge area, and an annular electrode surrounding said semispherical electrode with a spacing therefrom and extending away from said anode means more than said semispherical electrode; a gas inlet having an opening toward said preionization discharge area; and an electromagnet surrounding said main discharge area so as to generate a radial magnetic field therein, whereby gas from said preionization discharge area is ionized into Hall ions and accelerated in said main discharge area.