The SNS Moderator Demonstration Facility

Abstract

We describe a moderator demonstration facility at the Spallation Neutron Source (SNS). We will use the Beam Test Facility (BTF) at SNS to provide a moderator neutronics test stand with which we will verify the performance gains expected from the innovative moderator concepts central to the SNS Second Target Station. These concepts include large-volume para-hydrogen moderators and high-brightness moderators, as well as new moderator materials. The BTF provides a test facility for the new Radio-Frequency Quadrupole accelerator (RFQ) to be installed at SNS and produce a pulsed H− beam of 2.5 MeV energy. We will add to the BTF a beam chopper similar to that already used in the SNS at the RFQ exit, various beam transport components, a neutron-producing target, a cryogenic moderator test stand, a reflector-shielding assembly, and a performance assessment neutron beamline.