A novel neutrino detection system

Abstract

We describe a new neutrino (ν) detection technique which greatly enhances signal-to-noise ratios ( S/ N) for a variety of experiments with medium energy neutrino beams. This technique involves the simultaneous detection of a lepton and a neutron in various final states of ν induced interactions. We take as an example the reaction ν e p→ e + n and demonstrate the feasibility of detecting the neutron in fast (≲ 30 ns) time coincidence with the positron trigger. The detection efficiency for 1–3 MeV neutrons by proton recoil in a liquid scintillator test module is shown to be 40%. Monte Carlo studies indicate an e ±n detection efficiency of 6% for a sample 6.1 ton detector, to be compared with an e + only detection efficiency of 32%. Cosmic ray and beam induced background rates are reduced by over a factor of 200, improving S/ N by a factor of 40. We show that this sample detector, consisting of walls of liquid scintillator modules interspersed with drift chambers and surrounded by active anti-coincidence and passive shielding, can achieve the same sensitivity to ν e p→ e + n as a detector three times its size. We point out the utility of such a detector for various potential neutrino experiments and facilities; i.e., the proposed High Intensity Los Alamos Neutrino Facility.