System and method for neutralizing an ion beam using water vapor
 An improved ion beam neutralizer (22) is provided for neutralizing the electrical charge of an ion beam (28) output from an extraction aperture (50). The neutralizer comprises a source of water (52); a vaporizer (54) connected to the source of water; a mass flow controller (56) connected to the vaporizer; and an inlet (60) connected to the mass flow controller. The vaporizer (54) converts water from the source (52) from a liquid state to a vapor state. The mass flow controller (56) receives water vapor from the vaporizer (54) and meters the volume of water vapor output by a mass flow controller outlet (66). The inlet (60) is provided with an injection port (68) located proximate the ion beam extraction aperture (50) and receives the metered volume from the outlet (66). The injection port (68) is positioned near the extraction aperture so that the ion beam and the water vapor interact to neutralize the ion beam. The improved ion beam neutralizer (22) is especially effective in low energy (less than ten kilo-electron volts (10 KeV)) beam applications. 
Eaton Corporation
H H
H01J H01J
inventional additional
Victor Jiong Frank
Benveniste Chen Sinclair