Measurement of indoor natural neutron spectrum with a Bonner sphere spectrometer
HU Qingdong1, ZENG Zhi1, MA Hao1, CHENG Jianping1, LI Junli1, ZHANG Hui1, WANG Xin1, WU Zhen1,2
1. Key Laboratory of Particle and Radiation Imaging of the Ministry of Education, Department of Engineering Physics, Tsinghua University, Beijing 100084, China;
2. Nuctech Company Limited, Beijing 100084, China
Abstract：A Bonner sphere spectrometer was used to measure indoor natural neutron spectra in Beijing with the neutron energy spectrum obtained using an unfolding procedure with a genetic algorithm. The spectra and fluence-to-dose conversion coefficients gave a neutron flux of 2.83×10-3 cm-2·s-1 and a neutron ambient dose equivalent of (1.5±0.1) nSv/h for neutron energy below 20 MeV. The total neutron flux was 3.54×10-3 cm-2·s-1 and the total neutron ambient dose equivalent was (2.1±0.1) nSv/h which are comparable with the dose of (2.3±0.2) nSv/h measured by a 3He neutron monitor. The results are consistent with other measurements at similar latitudes, which verifies the reliability of this instrument and the indoor neutron dose equivalent in Beijing.
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2015, Vol. 55 
