Multi-layer plastic scintillation detector for intermediate- and high-energy neutrons with n-γ discrimination capability

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2017-09, Vol.866, p.118-128
• Main Authors: Yu, L., Terashima, S., Ong, H.J., Chan, P.Y., Tanihata, I., Iwamoto, C., Tran, D.T., Tamii, A., Aoi, N., Fujioka, H., Gey, G., Sakaguchi, H., Sakaue, A., Sun, B.H., Tang, T.L., Wang, T.F., Watanabe, Y.N., Zhang, G.X.
• Format: Article
• Language: English
• Subjects: [formula omitted]-[formula omitted] discrimination under high-counting rate; Monte Carlo simulation; Multi-layer plastic scintillators; Range of secondary particle
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2017.05.044

A new type of neutron detector, named Stack Structure Solid organic Scintillator (S4), consisting of multi-layer plastic scintillators with capability to suppress low-energy γ rays under high-counting rate has been constructed and tested. To achieve n-γ discrimination, we exploit the difference in the ranges of the secondary charged particles produced by the interactions of neutrons and γ rays in the scintillator material. The thickness of a plastic scintillator layer was determined based on the results of Monte Carlo simulations using the Geant4 toolkit. With layer thicknesses of 5 mm, we have achieved a good separation between neutrons and γ rays at 5 MeVee threshold setting. We have also determined the detection efficiencies using monoenergetic neutrons at two energies produced by the d+d→n+3He reaction. The results agree well with the Geant4 simulations implementing the Liège Intranuclear Cascade hadronic model (INCL++) and the high-precision model of low-energy neutron interactions (NeutronHP).