Some effects of magnetic field on a hollow cathode ion source

A simple hollow cathode "cold wall" dc gaseous ion source with magnetic field was investigated. Parameters of the plasma and ion beam were measured as a function of magnetic field. The extracted ion current shows a nonmonotonic behavior as function of magnetic field strength but the magnetic field distribution had only little influence on the current-voltage characteristics and on all other derived plasma and beam parameters. Analysis of our experimental conditions indicates that the observed nonmonotonic behavior is associated with a change in the ratio of electron Larmor radius to cathode sheath thickness. (C) 2004 American Institute of Physics.