Construction and test of a single sphere neutron spectrometer based on pairs of 6Li-and 7Li-glass scintillators

• Published in: Radiation measurements Vol. 127; p. 106148
• Main Authors: Zou, Yisheng, Zhang, Weihua, Li, Chunjuan, Liu, Yina, Luo, Hailong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2019
• Subjects: 6Li- and 7Li-glass scintillator; Energy response calibration; Monte Carlo simulation; Single sphere neutron spectrometer (SSNS); 6Li- and 7Li-glass scintillator; Energy response calibration; Monte Carlo simulation; Single sphere neutron spectrometer (SSNS)
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/j.radmeas.2019.106148

A single sphere neutron spectrometer (SSNS) was designed to measure the neutron energy spectrum in mixed radiation fields. The spectrometer consisted of a 30 cm diameter single polyethylene moderating sphere with 19 pairs of 6Li- and 7Li-glass scintillator detectors located at the orthogonal x-, y-, z-axis. The glass scintillator detector was composed of glass scintillator, light guide and photomultiplier tube. The output signals from each detector were processed and read out by a charge division resistance network and an electronic system. The thermal neutron counts were discriminated by subtracting the signal counts of 7Li-glass scintillator detector from the signal counts of 6Li-glass scintillator detector at the same position. The neutron energy response of the SSNS was calibrated in mono-energetic neutron fields (144 keV, 250 keV, 565 keV, 1.2 MeV, 2.5 MeV, 14.8 MeV) based on the 5SDH-2 tandem accelerator in China Institute of Atomic Energy, which was also simulated from 0.0253eV to 19 MeV by the Monte Carlo method. Finally, a241Am–Be neutron energy spectrum and the ambient dose equivalent values were measured using the SSNS. The deviation between the experimental result of the SSNS and the reference value was 2.6%. •Pairs of 6Li- and 7Li-glass scintillator detectors can discriminate the neutron from photon/other particles.•The Single sphere neutron spectrometer (SSNS) can realize the measurement like Bonner sphere neutron spectrometer.•The energy response of the SSNS was simulated by FLUKA code and calibrated in mono-energetic neutron radiation fields.