Fundamental characteristics of beam extraction from a Hall-type accelerator working with permanent magnets were investigated. Ions were extracted by an axial electric field Ez in a small annular plasma channel with a radial magnetic field Br. Effects of discharge current and voltage, length of discharge channel, and gas flow rate were examined. It can deliver a large beam current density of more than 100 mA cm2 with low beam energy of 50 eV. By biasing an additional plasma chamber attached at the extraction area, the beam energy was controlled independently of the beam current.
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