A D 2 O detector for flux normalization of a pion decay-at-rest neutrino source

Abstract

We report on the technical design and expected performance of a 592 kg heavy-water-Cherenkov detector to measure the absolute neutrino flux from the pion-decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS). The detector will be located roughly 20 m from the SNS target and will measure the neutrino flux with better than 5 % statistical uncertainty in 2 years. This heavy-water detector will serve as the first of a 2-module detector system to ultimately measure the neutrino flux to 2 to 3 % at both the first target station as well as at the planned second target station of the SNS. This detector will significantly reduce a dominant systematic uncertainty for neutrino cross-section measurements at the SNS, increasing the sensitivity of searches for new physics.