Non-equilibrium Correction of 218Po for Measuring Radon Exhalation Rate
TAN Yan-liang1,2,XIAO De-tao2,ZHAO Gui-zhi2,ZHOU Qing-zhi2,XIAO Tian1,ZHOU Yi1
1. Depatrment of Physics and Electronics, Hengyang Normal University, Hengyang, Hunan 421008, China
2. School of Nuclear Science & Technology, University of South China, Hengyang, Hunan 421001, China
Abstract 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 chi-square value corrected by theoretical model is small than that of traditional model,this shows that the corrected theoretical model is more realistic.The theoretical model can be applied to develop and improve the instrument for measuring radon exhalation rate.
2012, Vol. 33 
