Uncertainty Evaluation for the Calibration Factor of β-ray Dosemeters
-
摘要: 为准确评估β射线剂量仪校准因子的不确定度,将经过溯源的薄窗电离室放置在β射线辐射场的测量点处进行测量得到剂量率参考值,然后采用替代法将β射线剂量仪放在同一位置进行测量得到指示值,通过二者的比值得到β射线剂量仪的校准因子,并对校准因子的不确定度进行评定。不确定度的来源主要包括参考辐射场的均匀性、替代法测量过程中位置的一致性、显示值的统计标准偏差等。结果表明在校准过程中,通过提高参考辐射场的均匀性和参考位置的一致性可以改善校准因子的不确定度。Abstract: To accurately evaluate the uncertainty in the calibration factor of a β-ray dosemeter, a traceable thin window ionization chamber was used to measure the reference dose rate at the reference position of the β-ray radiation field, and then the β-ray dosemeter was placed in the same position for measurement to obtain the indicated value. The calibration factor of the β-ray dosemeter was obtained, and the uncertainty in the calibration factor was evaluated. The main sources of uncertainty include the uniformity of the reference radiation field, the uniformity of the position in the measurement process of the substitution method, and the statistical standard deviation of the indicated value. The results show that in the calibration process, the uncertainty in the calibration factor can be reduced by improving the uniformity of the reference radiation field and the uniformity of the reference position.
-
Key words:
- metrology /
- β-ray /
- dose equivalent /
- calibration factor /
- uncertainty
-
表 1 β射线剂量仪校准因子的不确定度评价
Table 1. Uncertainty evaluation for the calibration factor of a β-ray dosemeter
第一步:参考标准 A类 (%) B类 (%) 溯源至上级标准的刻度因子 3.4 辐射质差异 - 标准的长期稳定性 0.5 温度气压修正 0.05 0.1 测量标准偏差 0.1 光子剂量与总剂量比值 0.02 转换因子 0.51 第一步 相对合成标准不确定度 0.11 3.48 第二步:待校仪表 读数标准偏差 0.5 与测量点位置的差异 3.0 辐射场不均匀 5.0 第二步 相对合成标准不确定度 0.50 5.83 相对合成标准不确定度 6.81 扩展不确定度(k=2) 14 -
[1] 李景云. 肢端剂量计和核设施弱贯穿辐射(主要是β辐射)的辐射防护监测[J]. 辐射防护, 2003, 23(5): 300-307. doi: 10.3321/j.issn:1000-8187.2003.05.005 [2] 李景云. β剂量仪和个人剂量计校准[J]. 辐射防护, 2003, 23(4): 1-15. [3] 孙亮, 李士骏. 电离辐射剂量学基础[M]. 第三版. 北京: 中国原子能出版社, 2014: 16-30. [4] 中华人民共和国国家质量监督检验检疫总局. 用于校准剂量仪和剂量率仪及确定其能量响应的 X和γ参考辐射 第1部分 辐射特性及产生方法: GB/T 12162.1-2000 [S]. 北京: 中国标准出版社, 2000. [5] 中华人民共和国国家质量监督检验检疫总局. 用于校准剂量仪和剂量率仪及确定其能量响应的 X和γ参考辐射 第2部分: 辐射防护用的能量范围为8 keV~1.3 MeV和4 MeV~9 MeV的参考辐射的剂量测定: GB/T 12162.2-2004 [S]. 北京: 中国标准出版社, 2004. [6] 中华人民共和国国家质量监督检验检疫总局. 用于校准剂量仪和剂量率仪及确定其能量响应的X和γ参考辐射 第3部分: 场所剂量仪和个人剂量计的校准及其能量响应和角响应的测定: GB/T 12162.3-2004 [S]. 北京: 中国标准出版社, 2004. [7] 吕雅竹, 赵瑞, 李德红, 等. X射线剂量当量仪校准因子不确定度评估[J]. 计量学报, 2020, 41(9): 1133-1137. doi: 10.3969/j.issn.1000-1158.2020.09.16 [8] 宋飞, 赵瑞, 丁卫撑, 等. X射线环境辐射监测仪器校准方法的研究[J]. 计量学报, 2021, 42(9): 1237-1243. doi: 10.3969/j.issn.1000-1158.2021.09.19 [9] International Organization for Standardization. Nuclear energy —Reference beta-particle radiation-Part 1: Methods of production: ISO 6980.1-2019[R]. Geneva: ISO, 2019. [10] 中华人民共和国国家质量监督检验检疫总局. β参考辐射 第1部分: 产生方法: GB/T 12164.1-2008[S]. 北京: 中国标准出版社, 2008. [11] International Organization for Standardization. Nuclear energy — Reference beta-particle radiation — Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field: ISO 6980.2-2019[R]. Geneva: ISO, 2019. [12] International Organization for Standardization. Nuclear energy — Reference beta-particle radiation — Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence: ISO 6980.3-2019[R]. Geneva: ISO, 2019. [13] Joint Committee for Guides in Metrology. Evaluation of measurement data - Guide to the expression of uncertainty in measurement: JCGM 100: 2008[R]. Paris: JCGM, 2008. [14] 国家质量监督检验检疫总局. 测量不确定度评定与表示: JJF 1059.1-2012[S]. 北京: 中国标准出版社, 2012. [15] 靳浩元, 刘军. 测量不确定度的评定方法及应用研究[J]. 计量科学与技术, 2021, 65(5): 124-131. doi: 10.12338/j.issn.2096-9015.2020.9002 [16] International Atomic Energy Agency. Calibration of Radiation Protection Monitoring Instruments: Safety Series No. 16[R]. Vienna: IAEA, 2000. [17] International Organization for Standardization. Reference beta-particle radiation — Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence: ISO 6980.3-2006[R]. Geneva: ISO, 2006. [18] 中华人民共和国国家质量监督检验检疫总局. β参考辐射 第3部分: 场所和个人剂量仪的校准及其能量响应和角响应的确定: GB/T 12164.3-2013 [S]. 北京: 中国标准出版社, 2013. [19] International Electrotechnical Commission. Radiation protection instrumentation- measurement of personal dose equivalents Hp(10), Hp(3) and Hp(0.07) for X, Gamma, neutron, and Beta radiations- direct reading personal dosemeters: IEC 61526-2020[R]. Geneva: IEC, 2020.