A new grid-type electron filter for volume-production negative-ion source

A new system providing continuous generation of broad negative-ion beam is described and characterized. The key element of the system is the grid-type electron filter allowing the formation without magnetic field of a stationary highly electronegative plasma which can be biased negatively with respect to a relatively high-area electrode that allows to extract the negative ions. Measurements of negative-ion energy distribution functions conducted using a magnetically filtered energy analyzer show broad (250mm) negative-ion beam formation with controllable energy starting from several eV. A conclusion is made about the possibility of practical application of the grid-type electron filter in negative ion sources for electric propulsion and etching technologies. Copyright (C) EPLA, 2012