Patent ID: 7820981

Claim:
An ion generating system for generating an ion beam comprising: a vaporizer of solid feed material for producing vapor of the material, an ion source and extraction electrode within a vacuum housing, and a reactive gas cleaning system, the ion source comprising an ionization chamber connected to a high voltage power supply and having an inlet for vapor of the material from the vaporizer, an energizeable ionizing system for ionizing the vapor within the ionization chamber and an extraction aperture that communicates with the vacuum housing, the vacuum housing evacuated by a vacuum pumping system, the extraction electrode disposed in the vacuum housing outside of the ionization chamber, aligned with the extraction aperture of the ionization chamber and adapted to be maintained at a voltage below that of the ionization chamber to extract ions through the aperture from within the ionization chamber to form the ion beam, surfaces of the ion generating system being susceptible to accumulating deposits of feed material or related contaminant during operation of the ion source, and the reactive gas cleaning system operable when the ion source is de-energized to provide a flow of reactive gas into and through the ionization chamber and through the ion extraction aperture to react with and remove the deposits on at least some of the surfaces of the ion generating system.