Neutron backgrounds in the Ricochet experiment

Abstract

This paper explores the impact of neutron backgrounds on the Ricochet experiment. The purpose of the Ricochet experiment is to determine the existence of sterile neutrinos via coherent neutrino-nucleus scattering. Coherent neutrino-nucleus scattering is an ideal detection method because it is a neutral current process. All active neutrino flavors will therefore be detected uniformly (no non-active, or sterile neutrinos will be detected because they do not couple to the Z boson). By varying the distance between the detector and the neutrino source, we consider deficits in neutrino flux to be evidence of oscillation to a fourth, non-active neutrino. Neutron backgrounds could interfere with neutrino detection. We therefore calibrate and employ Neutral Current Detectors (NCD's) for the purpose of neutron detection to measure the expected neutron spectrum incident on the detector. We furthermore design a Monte Carlo simulation to model the expected neutron capture rate of the neutrino detector in this setup.