摘要
采用活性炭盒测氡析出率的方法已成为国内外普遍采用的一种常规测量方法,活性炭盒的探测效率是该方法的关键参数。由于现有仪器很难直接测量活性炭盒中的氡活度,因而活性炭盒氡活度的测定成为校准活性炭盒探测效率的难点。本文提出了一种解决活性炭盒氡活度测定问题并校准活性炭盒探测效率的方法。通过测量活性炭盒泄放的氡的活度和活性炭盒泄放氡气前后的γ净计数率,推导出活性炭盒探测效率的计算公式并设计对应的校准方法。利用该方法对内直径63mm、内高度32mm的活性炭盒的探测效率进行了5次校准,平均探测效率为6.57%±0.26%。根据活性炭盒以及γ能谱测量装置,设计蒙特卡罗计算模型,探测效率的模拟结果为6.92%,与实验结果相差5%,说明该活性炭盒探测效率的校准方法是准确和可靠的。
Measuring radon exhalation rate from materials surface by activated charcoal canister is a common method at home and abroad.In this method,the detection efficiency of activated charcoal canister is essential but difficult to be determined because of the lack of ready-made instruments.A new method was presented to calibrate the detection efficiency by avoiding determining the radon activity of activated charcoal canister.By means of radon activity released from activated charcoal canister and the net γ-ray counting rates of this canister before and after exposure,the equation of detection efficiency was derived and the corresponding calibration method was designed.Using this method,the detection efficiency of activated charcoal canister with diameter of 63 mm and heightof 32 mm was calibrated for 5 times,and the average result is 6.57%±0.26%.Monte Carlo method was used to simulate the above-mentioned activated charcoal canister.The simulation result of detection efficiency is 6.92%,which is in agreement with the result of experiments by the proposed method with error of 5%.The above results show that the presented method is accurate and reliable.
作者
李承文
乐仁昌
陈林
LI Chengwen,LE Renchang,CHEN Lin(College of Physics and Energy,Fujian Normal University,Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, Fuzhou 350117, Chin)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2018年第6期1113-1117,共5页
Atomic Energy Science and Technology
基金
福建省自然科学基金资助项目(2017J01554)
关键词
氡
Γ能谱仪
活性炭盒
探测效率
radon
γ-ray spectrometer
activated charcoal canister
detection efficiency
