利用自主研发的多球中子谱仪对北京市某室内环境中子能谱及剂量率进行了测量。从中子能谱获得了能量低于20 MeV的环境中子注量率为2.83×10-3cm-2·s-1, 估算出环境中子总注量率为3.54×10-3cm-2·s-1; 利用中子注量与周围剂量当量转换系数计算出了能量低于20 MeV中子周围剂量当量率为(1.5±0.1) nSv/h, 总中子周围剂量当量率为(2.1±0.1) nSv/h, 与中子剂量仪测量值(2.3±0.2) nSv/h基本一致。该文测量结果与相近纬度比较相差不多, 可以为评估北京室内环境中子剂量提供参考。
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.
关键词
多球中子谱仪 /
环境中子 /
能谱 /
遗传算法 /
中子剂量
Key words
Bonner sphere spectrometer /
natural neutrons /
spectrum /
genetic algorithm /
neutron dose
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