A Cusped Field H- Ion Source for LAMPF

Abstract

The addition of the Proton Storage Ring (PSR) to LAMPF requires the development of a more intense H/sup -/ ion source. The goals of this development program are to produce a beam of sufficient quality to match the acceptance of the accelerator and of sufficient intensity and duty factor to satisfy PSR operation as well as existing LAMPF requirements. The ion source concept best suited to these demands is the multi-cusp negative ion source being developed at LBL. The H/sup -/ ion source development was carried out on the high-voltage test stand in the LAMPF injector complex. The test stand, upgraded for the project, provides both unanalyzed and mass-analyzed beams to appropriate emittance scanning stations. Beam currents are measured using both beam current toroids and biased Faraday cups in both sections of the transport line. The emittance data are processed by the SEL 840 control computer at LAMPF. Ion source testing has been carried out using the extraction optics originally developed for the LAMPF duoplasmatron. Optics questions are being addressed by the plasma simulation code SNOW developed at Sandia. The accelerating column design will seek to minimize the divergence of the extracted beam and the predictions from SNOW will bemore » tested on the stand with actual H/sup -/ beams.« less