ORNL, Oak Ridge, Tennessee, USA
Six drift tube linac (DTL) cavities have been operating successfully at the Spallation Neutron Source (SNS). Each cavity is fed by a tapered ridge waveguide iris input coupler and a waveguide ceramic disk window. The original couplers and cavities have been in service for more than a decade. Design optimization and tuning of the couplers were initially performed prior to installation and commissioning of the cavities. Since each DTL cavity is unique, expensive, and fully utilized for neutron production, none of the cavity structure is available as a test cavity or a spare. Maintaining spares for operations and for future system upgrade, test setup of the iris couplers for precision tuning is needed. Ideally a smaller cavity structure may be used for pretuning and RF conditioning of the iris couplers as a test cavity or a bridge waveguide. In this paper, study of using a single cell cavity for the iris tuning and conditioning is presented along with the 3D simulation results.
ORNL, Oak Ridge, Tennessee, USA
ORNL RAD, Oak Ridge, Tennessee, USA
The Spallation Neutron Source (SNS) accelerator sys-tems have been performing continuously and progressively since commissioning in 2006 to deliver the neutrons to beamlines. The 1.4 MW design beam power has been demonstrated during 24/7 operation while developments and investigations for system improvements are still ongoing to achieve the full design beam power and availability. Numerous difficulties that impeded reaching the full performance of the SNS accelerator systems have been identified and are being eliminated through repairs, upgrades, and developments. In this report, operational performance and developments of the accelerator systems are presented along with the efforts for future upgrades of the SNS.
ORNL, Oak Ridge, Tennessee, USA
ORNL RAD, Oak Ridge, Tennessee, USA
The Beam Test Facility (BTF) has been constructed to validate the performance of the new RFQ, to study ion source improvements, and to support neutron moderator development and six-dimensional phase space measure-ments for SNS. The BTF includes an H− ion source, Ra-dio-Frequency Quadrupole (RFQ), and Medium Energy Beam Transport (MEBT) beam diagnostics systems. A spare RFQ was built and fully RF tested in the BTF and will be installed in the SNS linac in the future. The test stand is ready to run with the H− ion beam through the new RFQ to fully validate the RFQ performance. The RFQ was designed to have the beam characteristics iden-tical to the existing RFQ with improved operational relia-bility and stability. The H− RF plasma ion source system includes new high power RF components for improved front-end system performance.