摘要
仿真人体模型肺中镅、钚、铀沉积量的测量是活体同等测量技术的对照基础。将肌肉组织、肺组织等效材料制成吸收片,用不同γ谱仪测量出其对241Am源不同特征X射线、γ射线(<60 keV)的吸收系数;选取241Am的59 keV特征峰并用γ能谱分析定量测定其放射性活度;利用工业CT获得人体模型肺检区肌肉组织、肺组织等效材料厚度及肋骨的间隙尺寸。全面分析了仿真人体模型肺中点沉积241Am测量系统的性能、水平、可靠性和准确度,研究了影响定量测量的因素和校正方法,检验了定量分析的可靠性,分析了测量误差的来源。
The measurement of thedeposit quantity of Am, Pu, U in the manikin is the comparison base of the same measurement of human body. The absorption pieces are made by the equivalent of musculature and lung tissue. Their absorption coefficients of X-ray and γ- ray （〈60 keV） from ^241Am source were measured hy different γ-ray spectrum instruments. The 59 keV characteristic peaks of 241 Am were selected and the activity of radioactivity was quantitatively measured by γ-ray energy- spectrum. The thickness data of musculature and lung tissue and the clearance of ribs in the lung-examined area of manikin have been acquired by industrial-CT. The reliability and accuracy of 241 Am survey system of dot deposits in manikin lung were fully researched. The authors have studied correct methods of the factors influencing quantitative measurements and tested the reliability of quantitative analysis. According to the formula calculation, the minimal quantities of dot deposits for Am in the lungs of male and female manikins are 9. 67 × 10^-11 g and 6. 46 ×10^-11 g, respectively, and the quantitative survey limit of dot deposits are 3. 02 ×10^-10 g and 2. 02 ×10^-10 g, respectively, the minimal quantities of dot deposits for Pu are 4. 5 × 10^-8 g and 3. 0× 10^-8 g, respectively, and the quantitative survey limits of dot deposits are 1.4×10^-7 g and 9.39 × 10^-8 g, respectively, the minimal quantity of dot deposits for U is 7.01×10^-5 g, and the quantitative survey limit is 2.2×10^-4 g. The paper introduces the sources of the measurement errors. The primary factors which affect the quantitative analysis results of nuclides in human body e. g. Am deposit quantity, are the uncertainties of calibration sources and the accuracy of the musculature thickness. By analysing the experiment data and error sources, the authors draw the conclusion that the maximal error of γ-ray activity quantitative analysis in the model lung of manikin is 10.5 %.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2005年第6期621-632,共12页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家"863计划"项目(2003AA421100)
国家自然科学基金资助项目(40574059)
关键词
仿真人体模型
沉积量
γ能谱分析
探测限
放射性核素
artificial manikin
deposit quantity
γ-ray energy-spectrum analysis
survey limit
radioactive nuclide
