Abstract
The U.S. Spallation Neutron Source (SNS) will require substantially higher average and pulse H- beam currents than can be produced from conventional ion sources such as the base line SNS source. H- currents of 40-50 mA (SNS operations) and 70-100 mA (power upgrade project) with an rms emittance of 0.20-0.35 Pi mm mrad and a ~7% duty factor will be needed. We are therefore investigating several advanced ion source concepts based on RF excitation. First, the performance characteristics of an external antenna source based on an Al2O3 plasma chamber combined with an external multicusp magnetic configuration, an elemental Cs system, and plasma gun will be discussed. Second, the first plasma measurements of a helicon-driven H- ion source will also be presented.
