Design and commissioning of the Beam Test Facility at the Spallation Neutron Source

The Beam Test Facility (BTF) originally built to verify the spare RFQs at the Spallation Neutron Source (SNS) possesses the additional capability to carry out high intensity beam experiments with unique capabilities. These capabilities include a full 6D phase space measurement system, and a beam line extension for studying the propagate beam dynamics including halo development under different match conditions. A phase space density plot method that characterizes beam halo is utilized in the design of the beamline. Simulations demonstrate that the beamline design meets the requirements for conducting beam halo research. Installation and commissioning of the BTF has been completed in stages, with the first stage demonstrating that the RFQ achieves the design parameters. Commissioning of the beamline extension has begun, and a high transmission efficiency has been achieved. More work, e.g. analysis of beam halo formation under different match conditions, will be done in the future.