Observation of Neutrons with a Gadolinium Doped Water Cerenkov Detector

TL;DR

This paper demonstrates a water Cerenkov detector doped with gadolinium that can detect neutrons and gamma-rays effectively, offering a low-cost solution for nuclear material monitoring and characterization.

Contribution

It introduces a novel gadolinium-doped water Cerenkov detector capable of simultaneously detecting neutrons and gamma-rays with high efficiency.

Findings

Sensitive to both gamma-rays and neutrons

Effective neutron detection via gadolinium capture

Potential for low-cost nuclear monitoring

Abstract

Spontaneous and induced fission in Special Nuclear Material (SNM) such as 235U and 239Pu results in the emission of neutrons and high energy gamma-rays. The multiplicities of and time correlations between these particles are both powerful indicators of the presence of fissile material. Detectors sensitive to these signatures are consequently useful for nuclear material monitoring, search, and characterization. In this article, we demonstrate sensitivity to both high energy gamma-rays and neutrons with a water Cerenkov based detector. Electrons in the detector medium, scattered by gamma-ray interactions, are detected by their Cerenkov light emission. Sensitivity to neutrons is enhanced by the addition of a gadolinium compound to the water in low concentrations. Cerenkov light is similarly produced by an 8 MeV gamma-ray cascade following neutron capture on the gadolinium. The large solid angle coverage and high intrinsic efficiency of this detection approach can provide robust and low cost neutron and gamma-ray detection with a single device.