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Li H.,Beijing University of Technology | Zhang L.,Solid Dosimetric Detector and Method Laboratory | Guo Q.,Beijing University of Technology
Radiation Protection Dosimetry | Year: 2012

Passive measuring devices are comprehensively employed in thoron progeny surveys, while the deposition velocity of thoron progeny is the most critical parameter, which varies in different environments. In this study, to analyse the influence of environmental factors on thoron progeny deposition velocity, an improved model was proposed on the basis of Lai's aerosol deposition model and the Jacobi's model, and a series of measurements were carried out to verify the model. According to the calculations, deposition velocity decreases with increasing aerosol diameter and also aerosol concentration, while increases with increasing ventilation rate. In typical indoor environments, a typical value of 1.26x10-5m s-1 is recommended, with a range between 7.6x10-7 and 3.2x10-4 m s-1. © The Author 2012. Published by Oxford University Press. All rights reserved. Source


Guo L.,Beijing University of Technology | Zhang L.,Solid Dosimetric Detector and Method Laboratory | Guo Q.,Beijing University of Technology
Journal of Radiological Protection | Year: 2016

The unattached fraction of radon progeny is one of the most important factors for radon exposure evaluation through the dosimetric approach. To better understand its level and variation in the real environment, a series of field measurements were carried out indoors and outdoors, and radon equilibrium equivalent concentration was also measured. The dose contribution of unattached radon progeny was evaluated in addition. The results show that no clear variation trend of the unattached fraction of radon progeny is observed in an indoor or outdoor environment. The average unattached fraction of radon progeny for the indoors and outdoors are (8.7 ± 1.6)% and (9.7 ± 2.1)%, respectively. The dose contribution of unattached radon progeny to total radon exposure is some 38.8% in an indoor environment, suggesting the importance of the evaluation on unattached radon progeny. © 2016 IOP Publishing Ltd. Source


Zhang L.,Beijing University of Technology | Zhang L.,Solid Dosimetric Detector and Method Laboratory | Guo Q.,Beijing University of Technology | Sun K.,Beijing University of Technology
Journal of Radioanalytical and Nuclear Chemistry | Year: 2015

To understand the level of radon exhalation rate from soil surface and its variation, a continuous measurement system was developed and applied for a field measurement in Beijing from April 2012 to February 2013. For seasonal variation, It was indicated by measurement results that radon exhalation rate was higher in spring (52.9 mBq m−2 s−1 in average) and lower in winter (17.0 mBq m−2 s−1 in average). The precipitation had a strong influence on the radon exhalation rate, usually radon exhalation rate increased quickly after rain. Daily variation of radon exhalation rate was also observed in spring, usually higher at noon and lower at midnight. © 2014, Akadémiai Kiadó, Budapest, Hungary. Source


Zhang L.,Solid Dosimetric Detector and Method Laboratory | Zhang L.,Beijing University of Technology | Guo Q.,Beijing University of Technology | Wang S.,Solid Dosimetric Detector and Method Laboratory
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

In order to evaluate thoron exposure in indoor environments, field measurements of both concentration and its size distribution were carried out in three typical rural residential houses in China, and exposure dose was evaluated using dosimetric method. Results show that the thoron progeny size distributions of rural indoor environments (AMAD: 76.5 nm; GSD: 2.7) are much smaller than those of urban (AMAD: 115 nm; GSD: 2.0), which makes the dose conversion factors of thoron in rural environments [307.4 nSv/(Bq m−3 h−1)] are much higher than those in urban [113.4 nSv/(Bq m−3 h−1)]. The highest thoron exposure (10.12 mSv a−1) was found in mud house of Yangjiang, the high radiation background area. © 2014, Akadémiai Kiadó, Budapest, Hungary. Source


Tang K.,State Key Laboratory of NBC Protection for Civilian | Tang K.,Solid Dosimetric Detector and Method Laboratory | Fan H.,Solid Dosimetric Detector and Method Laboratory | Cui H.,Solid Dosimetric Detector and Method Laboratory | And 2 more authors.
Radiation Protection Dosimetry | Year: 2014

The 3-D thermoluminescence spectra and glow curves of LiF:Mg,Cu,Si, LiF:Mg,Cu, LiF:Mg,Si and LiF:Cu,Si with low concentrations of Mg and Cu were measured and were compared with those with high concentrations to investigate further the role of dopants in LiF:Mg,Cu,Si material. The shape of glow curves of the four samples is similar; however, LiF:Cu,Si sample had no Mg dopant. It is concluded that the TL emission to be from self-trapped excitons in LiF, and this emission could be enhanced and altered by Mg, Cu and Si dopants in LiF:Mg,Cu,Si; all three dopants are necessary to obtain the bright TL emission and may be involved in the luminescence process; Mg seems to be the most essential dopant and Cu is involved in the trapping although the role of Mg dominates; both Cu and Si play a role in the main emission process and Cu also plays a role in reducing the emission around 610 nm. © The Author 2014. Source

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