A precise method to determine the activity of a weak neutron source using a germanium detector

TL;DR

This paper presents a precise method using a germanium detector and Monte Carlo simulations to accurately measure the weak neutron activity of an AmBe source through gamma-ray detection.

Contribution

The study introduces a novel experimental setup and simulation approach to determine neutron activity of weak sources with high precision.

Findings

Neutron activity measured as 307.4 +/- 5.0 n/s.

Method is consistent across different gamma-ray reactions.

Effective modeling of detector efficiency with Monte Carlo simulation.

Abstract

A standard high purity germanium (HPGe) detector was used to determine the previously unknown neutron activity of a weak americium-beryllium (AmBe) neutron source. Gamma rays were created through 27Al(n,n'), 27Al(n,gamma) and 1H(n,gamma) reactions induced by the neutrons on aluminum and acrylic disks, respectively. These gamma rays were measured using the HPGe detector. Given the unorthodox experimental arrangement, a Monte Carlo simulation was developed to model the efficiency of the detector system to determine the neutron activity from the measured gamma rays. The activity of our neutron source was determined to be 307.4 +/- 5.0 n/s and is consistent for the different neutron-induced gamma rays.