The spherical proportional counter is a large volume gaseous detector which finds application in several fields, including direct Dark Matter searches. When the detector is filled with nitrogen it becomes an effective neutron spectrometer thanks to the 14N(n,α)11B and 14N(n,p)14C reactions. Nitrogen, however, is a challenging operating gas for proportional counters and requires a high electric field strength to gas pressure ratio. Benefiting from the latest advances in spherical proportional counter instrumentation and simulation techniques, we report first neutron measurements at operating pressures of up to 1.8 bar. This achievement enhances the prospects of the spherical proportional counter to act as a neutron spectrometer appropriate for challenging environments, including underground laboratories, and industrial and medical settings.
@article{arxiv.2206.04331,
title = {Neutron spectroscopy with a high-pressure nitrogen-filled spherical proportional counter},
author = {I. Giomataris and S. Green and I. Katsioulas and P. Knights and I. Manthos and T. Neep and K. Nikolopoulos and T. Papaevangelou and B. Phoenix and J. Sanders and R. Ward},
journal= {arXiv preprint arXiv:2206.04331},
year = {2023}
}