title: A high-current light-ion injector for tandem accelerators.
abstract: A dual-source injector for tandem accelerators to produce negative ion currents of H, D, and He has been developed and built. The system consists of a central vacuum enclosure that accommodates two multicusp ion sources. Beam currents of several mA of H(-) and D(-) have been obtained by direct negative extraction of one of the multicusp ion sources. The yield for He(-) was optimized applying differentially pumped vacuum sections that support space compensation in the He(+) transport section a well as low neutralization loss of He(-) after charge exchange. In addition, an optimized extraction geometry and beam transport system enabled in excess of 10 mA He(+) within the low acceptance of the charge exchange canal. Early measurements yielded approximately 50 microA for He(-) using Li as a charge exchange medium, but currents over 100 microA are anticipated if Na would be used.
authors.affiliation: High Voltage Engineering Europa B.V., P.O. Box 99, 3800 AB Amersfoort, The Netherlands.
authors.forename: G W W
authors.initials: GW
authors.lastname: Quax
authors.forename: A
authors.initials: A
authors.lastname: Gottdang
authors.forename: D J W
authors.initials: DJ
authors.lastname: Mous