同位素中子源参考辐射能谱测量及模拟中子谱分析  

Measurement of Reference Radiation Spectrum of Isotopic Neutron Source and Analysis of Simulated Neutron Spectrum

作　　者：李自平 唐智辉 李达 冯梅[2] 蒋虹 李多宏 周志波 LI Ziping;TANG Zhihui;LI Da;FENG Mei;JIANG Hong;LI Duohong;ZHOU Zhibo(State Nuclear Security Technology Center,Beijing 102401,China;China institute of Atomic Energy,Taiyuan 030006,China)

机构地区：[1]国家核安保技术中心,北京102401 [2]中国辐射防护研究院,太原030006

出　　处：《同位素》2023年第2期226-233,I0006,共9页Journal of Isotopes

摘　　要：不同成分中子参考辐射场是对中子防护材料性能测试的基本条件。为获得较理想的测试中子防护材料的中子参考辐射场,构建基于3He正比计数管的多球中子能谱测量系统,对基于^(241)Am-Be和^(252)Cf中子源的中子辐射场慢化情况进行MCNP模拟和能谱实验测量。为准确判断实验室校准参考位置的中子散射情况,基于多球中子能谱测量系统,开展了中子散射成分测量。采用ICRP推荐的注量-剂量转换系数对能谱进行了剂量率转化,与使用长计数器的测量结果进行比较,发现在校准参考位置的剂量率相对偏差≤20%。开展了聚乙烯慢化同位素中子源获得特定能谱的实验研究,进行了慢化谱的模拟计算和实验测量,两者结果符合较好。该工作为后续的中子计量测试和中子防护材料测试提供了可用的中子参考辐射场。The neutron reference radiation field of different components is the basic condition for the performance test of neutron shielding materials.In order to obtain an ideal neutron field for neutron protection material testing,a multi sphere energy spectrum measurement system based on 3He tube was constructed.The neutron radiation field slowing down condition based on^(241)Am-Be and^(252)Cf neutron sources was simulated and the energy spectrum was measured.In order to accurately judge the neutron scattering at the calibration reference position of the laboratory,the neutron scattering component measurement was carried out based on the multi sphere neutron spectrum measurement system.The dose rate conversion of the energy spectrum was carried out using the dose dose conversion coefficient recommended by ICRP.Compared with the results of the long counter,it was found that the deviation of the dose rate at the calibration position was not more than 20%.The experimental study on obtaining specific energy spectrum of polyethylene moderated isotope neutron source was carried out.The simulated calculation and experimental measurement of moderated spectrum were carried out,and the results were in good agreement.This work provides a useful neutron radiation field for the subsequent neutron metrology test and neutron protection material test.

关 键 词：中子能谱 中子参考辐射 散射中子 中子校准 

分 类 号：TL84[核科学技术—核技术及应用]