氡析出率测量中的^218Po非平衡修正  

Non-equilibrium Correction of ^218po for Measuring Radon Exhalation Rate

作　　者：谭延亮[1,2] 肖德涛[2] 赵桂芝[2] 周青芝[2] 肖田[1] 周毅[1] 

机构地区：[1]衡阳师范学院物电系,湖南衡阳421008 [2]南华大学核科学技术学院,湖南衡阳421001

出　　处：《计量学报》2012年第1期91-93,共3页Acta Metrologica Sinica

基　　金：国家自然科学基金项目（11075049）;湖南省研究生科研创新项目（CX2010B373）;衡阳师范学院英才支持计划

摘　　要：通过对传统的累积法测量氡析出率模型实验验证，发现得到的氡析出率明显偏低。对测氡仪器的工作原理与集氡罩中氡的浓度变化规律进行分析，发现是由于被测介质表面析出的氡不断进入集氡罩，^218Po与氡没有平衡，造成测量的氡浓度明显偏低。通过非平衡修正得到了修正后的氡析出率测量理论模型。利用修正后的该模型得到的介质表面氡析出率与参考值符合得较好，误差小于7％。此外比较优值函数的取值也可发现：修正后的理论模型优值函数的取值小于传统模型，这表明修正后的理论模型更符合实际，该理论模型可应用于氡析出率仪的研制与改进。By experimental verification base on traditional accumulation method, discoverd that the radon exhalation rate obtained is obviously low. Analysis of the operation principle of measuring instruments for radon and the variation of the radon concentration in the chamber, find that it is because of the radon exhaled from medium suface continuously and got into the chamber, ^218Po is not in equilibrium with radon, this make the radon concentration measured by instrument obviously low. The corrected theoretical model for measuring radon exhalation rate is obtained by non-equilibrium revision. The radon exhalation rate from medium surface obtained by corrected theoretical model match the reference value well and the error is less than 7%. Moreover, compare chi-square value of different model and find that the ehi-square value corrected by theoretical model is small than that of traditional model ,this shows that the correeted theoretical model is more realistic. The theoretical model can be applied to develop and improve the instrument for measuring radon exhalation rate.

关 键 词：计量学 氡析出率 累积法 非平衡修正 

分 类 号：TB98[一般工业技术—计量学]