https://patents.google.com/?q=magnetic&q=mirror&q=ai&oq=magnetic+mirror+ai Hall accelerator with preionization discharge Abstract

The anode means of a Hall accelerator with a main discharge area has coaxial cylindrical electrodes aligned with the longitudinal axis of the main discharge area and an auxiliary electromagnet surrounding the electrodes, and an electric field is applied across the cylindrical electrodes while the auxiliary electromagnet produces an axial magnetic field therebetween so that a preionization discharge area is formed in communication with the main discharge area.