Neutron spectroscopy with the Spherical Proportional Counter

TL;DR

This paper demonstrates the use of a novel spherical proportional counter for neutron spectroscopy, optimizing gas mixtures and operational parameters to detect thermal and fast neutrons effectively, including atmospheric neutrons.

Contribution

It introduces a new neutron detection method using a spherical proportional counter with optimized gas mixtures and operational settings.

Findings

Effective detection of thermal and fast neutrons from various sources.

Successful measurement of atmospheric neutrons across a wide energy range.

Comparison shows advantages over existing neutron counters.

Abstract

A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. Gas mixtures of $N_{2}$ with $C_{2}H_{6}$ and pure $N_{2}$ are studied for thermal and fast neutron detection, providing a new way for the neutron spectroscopy. The neutrons are detected via the ${}^{14}N(n, p)C^{14}$ and ${}^{14}N(n, \alpha)B^{11}$ reactions. Here we provide studies of the optimum gas mixture, the gas pressure and the most appropriate high voltage supply on the sensor of the detector in order to achieve the maximum amplification and better resolution. The detector is tested for thermal and fast neutrons detection with a ${}^{252}Cf$ and a ${}^{241}Am-{}^{9}Be$ neutron source. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also given.