Characterization of a commercial electron impact fast atom beam source

Apparatus has been designed and experiments conducted to fully characterize a commercial fast atom beam source, the Kratos Macro-FAB WG-548, which operates in the energy range 50 eV to 5 keV. The parameters measured include the variation in the proportion of neutrals in the total beam as functions of energy and pressure, energy spread of the beam, beam purity and beam divergence. The results of these measurements are presented and the problems associated with low neutral content, beam energy spread and beam contamination and displacement are discussed. The apparatus and experimental arrangements designed for the experiments are discussed, so that workers wishing to characterize other commercially available sources may do so without having to rely on scant information supplied by manufacturers. (author)