Computational Study of Primary Electron Confinement by Magnetic Fields in the Discharge Chamber of an Ion Engine

A computational investigation of the ability of different magnetic field shapes to confine primary electrons in a discharge chamber of an ion engine is performed. Ideal and actual magnetic fields are studied to gain an understanding of which magnetic field shape provides the most primary electron confinement. The simple, ideal field studies clearly show that particle collisions significantly reduce the confinement ability of a magnetic field. The design parameter studied for actual ring-cusp configurations is the number of magnetic rings used on the discharge chamber. This study indicates that adding additional magnet rings to the discharge chamber does not necessarily increase the confinement ability of the magnetic field. For the size discharge chamber studied in this work, increasing the number of magnetic rings reduces the confinement ability of the magnetic field.