Light Collection and Pulse-Shape Discrimination in Elongated Scintillator Cells for the PROSPECT Reactor Antineutrino Experiment

TL;DR

This study evaluates a long liquid scintillator detector's light collection and pulse-shape discrimination capabilities, optimizing design features for improved background rejection in reactor antineutrino detection.

Contribution

It provides new insights into the performance of elongated scintillator cells, including optimal configurations for light collection and neutron-gamma discrimination.

Findings

High light collection uniformity achieved along the cell

Effective neutron-gamma discrimination demonstrated

Design recommendations for enhanced MeV-scale response

Abstract

A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron/gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell long axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified.