摘要
辐射剂量仪表的准确测量是开展辐射防护工作的重要保障,根据ICRU中规定的实用量要求,需要在特定的参考辐射场中对其进行检定或校准。参考ISO 4037-1:2019,建立250~500 kV X射线窄谱系列参考辐射质,对所建辐射场的均匀性以及相应辐射质下的能谱进行研究。将由EGSnrc模拟的X射线能谱得到所建辐射质下的平均能量、分辨率以及实验测量得到的半值层值与ISO标准推荐值进行比较,结果均满足规范要求,表明新建辐射质准确可靠。利用A5电离室对新建辐射场中的空气比释动能进行测量,再根据X射线能谱信息计算得到的空气比释动能到剂量当量的转换系数,实现空气比释动能到周围剂量当量和个人剂量当量的转换,从而为各类辐射剂量仪表在该高能段的能量响应评价提供了测量条件,保证了量值的准确与可靠。
Accurate measurement of radiation dosimeter is an important guarantee for conducting radiation protection.According to the operational quantities in ICRU report,it is necessary to verify or calibrate it in the reference radiation field.Referring to the ISO 4037-1:2019,the narrow spectrum X-ray reference radiation quality in(250-500)kV was established,and the uniformity of the radiation field and the spectrum were studied.The spectrum and half value layer parameters of radiation quality were obtained by Monte Carlo simulation and experimental measurement,and were compared with the ISO recommended values.These results meet the requirements of the relevant specification,indicating that the new radiation quality is accurate and reliable.The A5 ionization chamber is used to measure the air kerma in the new radiation field.According to the conversion coefficient of the air kerma to dose equivalent calculated by the X-ray energy spectrum,the conversion of the air kerma to the ambient dose equivalent and the individual dose equivalent is realized,which provides the measurement conditions for the energy response evaluation of various radiation dose meters in the high-energy region,and ensures the accuracy and reliability of the measurement value.
作者
屈冰冰
赵瑞
吴金杰
鲁平周
李梦宇
李婷
马英杰
QU Bingbing;ZHAO Rui;WU Jinjie;LU Pingzhou;LI Mengyu;LI Ting;MA Yingjie(Chengdu University of Technology,Chengdu 610059;National Institute of Metrology,Beijing 100029)
出处
《辐射防护》
CAS
CSCD
北大核心
2024年第1期19-26,共8页
Radiation Protection
基金
国家市场监督管理总局技术保障专项(2022YJ33)资助。
关键词
X射线
窄谱辐射质
空气比释动能
剂量当量
转换系数
X-ray
narrow spectrum radiation quality
air kerma
dose equivalent
conversion coefficient
