Ion pump having secondary magnetic field

摘要

An ion pump includes one or more anode pump cells, a cathode positioned in proximity to the one or more anode pump cells and a magnet assembly for producing a magnetic field in the one or more anode pump cells. An electric field is applied between the cathode and the one or more anode pump cells. The magnet assembly includes primary magnets of opposite polarities disposed on opposite ends of the anode pump cells and secondary magnets disposed on opposite sides of the anode pump cells. The magnet assembly may further include a magnet yoke which provides a magnetic flux return path. The magnet assembly produces a substantially uniform axial magnetic field in the one or more anode pump cells.