Status of the New SNS Injector and External Antenna Ion Source

The U.S. Spallation Neutron Source (SNS) now operates with 1.2 MW of beam power on target with the near term goal of delivering 1.4 MW and a longer-term goal of delivering >2 MW required by the planned Proton Power Upgrade (PPU) and Second Target Station (STS) projects. In early 2018 we plan to replace the entire 2.5 MeV injector configuration which includes the ion source, the Low Energy Beam Transport (LEBT) and the Radio Frequency Quadrupole accelerator (RFQ) with one which is currently being tested on a research accelerator called the Beam Test Facility (WIT) located at the SNS facility. This report first provides a description of the new injector: the ion source and the cage enclosure, the new LEBT support structure and the new RFQ. Since fall of 2016, this system has been tested extensively with regard to output beam current, beam persistence, emittance and energy. The results of these experiments employing both internal and external antenna ion sources will be summarized here showing the system to be capable of supporting SNS 1.4 MW operations with a significant margin as well as potentially meeting facility upgrade requirements. This represents a significant performance upgrade over the current SNS front end system with the compromised RFQ and will replace that system in early 2018.