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arXiv · 1611.04015

Development of a Bonner Sphere Neutron Spectrometer from a Commercial Neutron Dosimeter

M. C. Chu·K. Y. Fung·T. Kwok·J. K. C. Leung·Y. C. Lin·H. Liu·K. B. Luk·H. Y. Ngai·C. S. J. Pun·H. L. H. Wong
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Abstract

Bonner Spheres have been used widely for the measurement of neutron spectra with neutron energies ranged from thermal up to at least 20 MeV. A Bonner Sphere neutron spectrometer (BSS) was developed by extending a Berthold LB 6411 neutron-dose-rate meter. The BSS consists of a $^{3}$He thermal-neutron detector with integrated electronics, a set of eight polyethylene spherical shells and two optional lead shells of various sizes. The response matrix of the BSS was calculated with GEANT4 Monte Carlo simulation. The BSS had a calibration uncertainty of $\pm 8.6\%$ and a detector background rate of $(1.57 \pm 0.04) \times 10^{-3}$ s$^{-1}$. A spectral unfolding code NSUGA was developed. The NSUGA code utilizes genetic algorithms and has been shown to perform well in the absence of a priori information.

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M. C. Chu, K. Y. Fung, T. Kwok, J. K. C. Leung, Y. C. Lin, H. Liu, K. B. Luk, H. Y. Ngai, C. S. J. Pun, H. L. H. Wong. 2016-11-12. Development of a Bonner Sphere Neutron Spectrometer from a Commercial Neutron Dosimeter. https://doi.org/10.1088/1748-0221/11/11/p11005

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