摘要
设计了一种铝基碳化硼材料中^(10)B面密度的测试系统.该系统采用球形^(3)He正比计数器作为热中子探测器,以厚度为75 cm的高纯石墨慢化镅铍中子源后的出射中子作为实验源项.为屏蔽中子和γ射线,在慢化层外包裹有厚度为5 cm的含硼聚乙烯层和2 cm厚的铅层.设计了测量用准直系统,试验时,将面积大于探测器两倍的片状样品置于准直器前,测量有无样品时的探测器计数率,两者比较可得材料的热中子透射率.建立了标准样品的^(10)B面密度与热中子透射率关系,采用对数插值的方法,通过测量待测样品的热中子透射率计算其^(10)B面密度.实验测试结果表明,利用该系统可快速无损地测量材料中热中子吸收元素的面密度,且测量误差和测量不确定度都在合理的范围.
A test system for^(10)B areal density in aluminum-based boron carbide materials was designed.The system uses a spherical^3He proportional counter as the thermal neutron detector,and a 75 cm-thick high-purity graphite-moderated americium-beryllium neutron source is used as the experimental source term.In order to shield neutrons and gamma rays,a boron-containing polyethylene layer with a thickness of 5 cm and a lead layer with a thickness of 2 cm are wrapped around the moderator layer.A collimation system for measurement was designed.During the test,a sheet sample with an area larger than twice the detector was placed in front of the collimator to measure the detector count rate with or without the sample,and the thermal neutrons of the available materials were compared between the two.Transmittance.The relationship between the^(10)B areal density and thermal neutron transmittance of the standard sample was established,and the^(10)B areal density was calculated by measuring the thermal neutron transmittance of the sample to be tested by means of logarithmic interpolation.The experimental test results show that the system can quickly and non-destructively measure the areal density of thermal neutron absorbing elements in materials,and the measurement error and measurement uncertainty are within a reasonable range.
作者
唐智辉
王川
谷伟刚
方登富
王勇
务圣杰
韦应靖
张庆利
TANG Zhi-hui;WANG Chuan;GU Wei-gang;FANG Deng-fu;WANG Yong;WU Sheng-jie;WEI Ying-jing;ZHANG Qing-li(China Institute for Radiation Protection,Taiyuan 030006,China;Nuclear Power Operation Research Institute,Shanghai 200126,China)
出处
《核电子学与探测技术》
CAS
北大核心
2022年第5期828-834,共7页
Nuclear Electronics & Detection Technology
关键词
铝基碳化硼材料
^(10)B面密度
热中子透射率
热中子装置
aluminum-based boron carbide material
^(10)B areal density
thermal neutron transmittance
thermal neutron device
