A look ahead: Status of the SNS external antenna ion source and the new RFQ test stand

Abstract

The U.S. Spallation Neutron Source (SNS) now operates with ∼1 MW of beam power to target with the near-term goal of delivering 1.4 MW. Plans are being considered to incorporate a second target station into the facility which will require ∼2.8 MW of beam power. Presently, H− beam pulses (∼1 ms, 60 Hz) are produced by an RF-driven, Cs-enhanced, multi-cusp ion source which injects beam into an RFQ (Radio Frequency Quadrupole) accelerator that, in turn, feeds the SNS Linac. Currently the source/RFQ system delivers ∼35 mA of pulsed current to the linac which is mostly sufficient for 1.4 MW operations while ∼50 mA are needed for the second target station upgrade. This paper provides a look forward for the SNS by providing (i) the present and future SNS source/RFQ beam requirements and our plans to achieve these, (ii) a description and status of the external antenna ion source being developed for the replacement of the current internal antenna ion source, and (iii) a description and status of the newly constructed RFQ test facility.