A low energy neutrino-oscillation detector at the San Onofre nuclear reactor

The San Onofre experiment consists of a large liquid scintillation detector for studying neutrino oscillations with a projected sensitivity for Δm2 of 10-3 eV2 and a mixing angle sensitivity of sin22θ=0.1. The detector is a segmented 13 ton liquid scintillator. A novel scheme of neutron background rejection based on a positron annihilation coincidence requirement has been developed. Our detector will be installed at a distance of 650 m from the San Onofre reactors in Southern California, 20 mWe below surface. We employ a passive neutron buffer and an active muon veto to reduce the background. The event rate is expected to be 22/d with a signal-to-background of about 2:1. (authors). 8 refs., 3 figs