A Background-Free Direction-Sensitive Neutron Detector2 A Background-Free Direction-Sensitive Neutron Detector

TL;DR

This paper introduces a novel background-free, direction-sensitive neutron detector capable of measuring neutron flux, energy, and direction across various neutron energies, significantly improving detection sensitivity and specificity.

Contribution

The paper presents a new neutron detector design that eliminates common backgrounds and provides detailed neutron property measurements, including directionality and energy, with practical applications.

Findings

Can identify one gram of reactor-grade plutonium from one meter away in less than a minute.

Eliminates backgrounds from x-rays, gamma rays, beta particles, and cosmic rays.

Capable of detecting thermal, fission, and high-energy neutrons with distinctive features.

Abstract

We show data from a new type of detector that can be used to determine neutron flux, energy distribution, and direction of neutron motion for both fast and thermal neutrons. Many neutron detectors are plagued by large backgrounds from x-rays and gamma rays, and most current neutron detectors lack single-event energy sensitivity or any information on neutron directionality. Even the best detectors are limited by cosmic ray neutron backgrounds. All applications (neutron scattering and radiography, measurements of solar and cosmic ray neutron flux, measurements of neutron interaction cross sections, monitoring of neutrons at nuclear facilities, oil exploration, and searches for fissile weapons of mass destruction) will benefit from the improved neutron detection sensitivity and improved measurements of neutron properties made possible by this detector. The detector is free of backgrounds from x-rays, gamma rays, beta particles, relativistic singely charged particles and cosmic ray neutrons. It is sensitive to thermal neutrons, fission neutrons, and high energy neutrons, with detection features distinctive for each energy range. It is capable of determining the location of a source of fission neutrons based on characteristics of elastic scattering of neutrons by helium nuclei. The detector we have constructed could identify one gram of reactor grade plutonium, one meter away, with less than one minute of observation time.