作者机构：
[Tan, Yanliang] Hengyang Normal Univ, Dept Phys & Elect, Hengyang, Peoples R China.;[Tan, Yanliang; Xiao, Detao] Univ South China, Sch Nucl Sci & Technol, Hengyang, Peoples R China.
通讯机构：
[Tan, Yanliang] H;Hengyang Normal Univ, Dept Phys & Elect, Hengyang, Peoples R China.
关键词：
RAD7;Soil;Thoron exhalation rate
摘要：
Thoron exhalation rate can be obtained through the combination of the "accumulation chamber" technique and RAD7. Thoron's rapid decay causes the intake path and the air flow rate to become important factors in calibration. In field conditions, since the flow rate of the internal pump in RAD7 will change as the voltage of the battery decreases, the big drying tube is more suitable for a long measurement than the small drying tube. We developed the method for recalibration of the thoron concentration reading of RAD7 based on the calibration factor for 222Rn, and obtained the thoron exhalation rate from soil surface near by the Radon Laboratory of the University of South China. This method can be applied to develop and improve instruments for measuring the radon exhalation rate.
作者机构：
[Yanliang Tan; HongzhiYuan] Hengyang Normal University, Hengyang, China;[Yanliang Tan; Detao Xiao; Jian shan; Qingzhi Zhou; Tang Quan] University of South China, Hengyang, China;[Chunhong Wang; Senlin Liu] China Institute of Atomic Energy, Beijing, China
会议名称：
7th International Symposium on Radiation Safety and Detection Technology(第七届国际声辐射安全与检测技术研讨会)(ISORD-7)
会议时间：
2013-7-15
会议地点：
三亚
会议主办单位：
中国原子能科学研究院
会议论文集名称：
7th International Symposium on Radiation Safety and Detection Technology(第七届国际声辐射安全与检测技术研讨会)(ISORD-7)论文集
摘要：
There are many methods and instruments for measuring radon concentration, but only the electrostatic collection method can be used to measure and distinguish the radon and thoron concentration synchronously and continuously.
摘要：
A method and device for measuring radon by electrostatic collection without influence of environmental temperature and humidity. The device comprises a measuring cavity (1), a semiconductor detector (2), a high-voltage module (3), a sampling pump (4), a vacuum meter (5) and a regulating valve (6), wherein the regulating valve (6) is arranged on the air inlet channel of the cavity; the vacuum meter (5) and the sampling pump (4) are arranged on the air outlet channel of the measuring cavity in sequence; the semiconductor detector (2) is arranged on the upper part inside the measuring cavity and connected with one interface end of the high-voltage module through a wire, and the other interface end of the high-voltage module is connected with the shell of the measuring cavity through a wire. The method, achieved by reducing air pressure in the electrostatic collection measuring cavity below a certain threshold value, can make the efficiency of collecting positively charged 218Po particles on the surface of the detector by the electrostatic collection measuring cavity basically unchanged when the relative air humidity of external environment is changed from 0％ to 100％ in the working temperature range of 0 to 45 degrees, thereby the detecting efficiency is not changed with the change of temperature and humidity of the external environment, and the threshold value is related to a geometric factor of the measuring cavity and the electric field intensity distribution in the measuring cavity.
摘要：
A method and device for measuring radon by an electrostatic collection method without an influence of an environmental temperature and humidity is by reducing a pressure that in an electrostatic collection and measuring chamber to below a certain threshold value, in an operation temperature range of 0-45 degrees, and an air relative humidity of an external environment changing in 0％-100％, a collection efficiency of the collection and measuring chamber of the static electricity that collects positively charged 218Po particle to a surface of a semiconductor detector is basically unchanged, so when a temperature and a humidity of the external environment change, a detection efficiency does not change; the threshold value relates to a geometric factor and a distribution of an electric field intensity that in different measuring chamber. The device comprises a measuring chamber, a semiconductor detector, a high-voltage module, a sampling pump, a vacuum gauge, and a regulating valve. The regulating valve is installed on an inlet pipe of the measuring chamber. The vacuum gauge and the sampling pump are installed on an outlet pipe of the measuring chamber. The semiconductor detector is installed inside an upper portion of the measuring chamber, and is connected to an interface port of the high-voltage module by a wire. Another interface port of the high-voltage module is connected to a shell of the measuring chamber by a wire.
作者机构：
[申超; 肖德涛; 陈凌] School of Nuclear Science and Technology, University of South China, Hengyang 421001, China;[谭延亮] Department of Physics and Electronic Information Science, Hengyang Normal University, Hengyang 421008, China;[陈凌] China Institute of Atomic Energy, P. O. Box 275-24, Beijing 102413, China
通讯机构：
School of Nuclear Science and Technology, University of South China, China
摘要：
The radon exhalation rate from the medium surface is commonly derived using a scheme involving a radon detector and an accumulation chamber. The accumulation chamber accumulates the radon gas to make its concentration level inside the chamber detectable by the radon detector in the scheme. The common calculation method for deriving the exhalation rate is based on an assumption that the radon concentrations in the detector's internal cell and that in the accumulation chamber become equal with sufficient accumulation time. However, based on our recent experiments, this method tends to underestimate the actual exhalation rates as generated by our simulation facility. To correct this, we develop a new method for computing the exhalation rate based on the non-equilibrium concept. This paper presents the new method.
