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arXiv · 2107.02682

Neutron spectroscopy with N$_2$-filled high-pressure large-volume spherical proportional counters

I. Giomataris·S. Green·I. Katsioulas·P. Knights·I. Manthos·J. Matthews·T. Neep·K. Nikolopoulos·T. Papaevangelou·B. Phoenix·J. Sanders·R. Ward
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Abstract

Precise in-situ measurements of the neutron flux in underground laboratories is crucial for direct dark matter searches, as neutron induced backgrounds can mimic the typical dark matter signal. The development of a novel neutron spectroscopy technique using Spherical Proportional Counters is investigated. The detector is operated with nitrogen and is sensitive to both fast and thermal neutrons through the $^{14}$N(n, $\alpha$)$^{11}$B and $^{14}$N(n, p)$^{14}$C reactions. This method holds potential to be a safe, inexpensive, effective, and reliable alternative to $^3$He-based detectors. Measurements of fast and thermal neutrons from an Am-Be source with a Spherical Proportional Counter operated at pressures up to 2 bar at Birmingham are discussed.

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I. Giomataris, S. Green, I. Katsioulas, P. Knights, I. Manthos, J. Matthews, T. Neep, K. Nikolopoulos, T. Papaevangelou, B. Phoenix, J. Sanders, R. Ward. 2021-07-06. Neutron spectroscopy with N$_2$-filled high-pressure large-volume spherical proportional counters. https://doi.org/10.1088/1742-6596/2374/1/012144

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