Development of a toroidal-filter H- ion source

High brightness H- ion beams will be required for the next generation of accelerator-driven, neutron spallation sources. Volume H- ion sources have the potential for providing these beams at a high duty factor with moderate beam currents and with the long-term operational stability and reliability needed. We report on the results of a continuing study of the Los Alamos National Laboratory version of a toroidal-filter, volume H- ion source which was designed to provide such beams. The H- beam current, emittance, and electron loading have been measured with the source equipped with a 3- and a 10-mm-diam emission aperture and with several configurations of the plasma filter. The results are compared to beam simulations. copyright 1996 American Institute of Physics