New Approaches to Antineutrino Directionality

Abstract

The directional detection of electron antineutrinos undergoing inverse beta decay (IBD) has uses ranging from fundamental science (ex. sterile-neutrino searches, supernova physics) to industrial and even nonproliferation applications (ex. reactor analysis, fuel material, location). In this dissertation, we find that even under ideal conditions, the loss of directional information due to neutron scattering during thermalization and capture, limits traditional reactor-IBD detectors to a mean angular agreement of mean[cos(psi)] ~ 0.3, where psi is the difference angle between the true and reconstructed incoming antineutrino directions. We examine a proposed method and corresponding detector design which our simulations indicate could reach mean[cos(psi)] ~ 0.9, but is expected to struggle with background rejection and low data rates. By combining these approaches, we present a survey of novel reactor-IBD detectors designed to beat the limit imposed by neutron scattering while maintaining both a high signal rate and resilience against backgrounds. We discuss new related detection concepts and techniques as well.