School of Nuclear Science and Technology, University of South China, Hengyang, Hunan, 421001, China.
School of Nuclear Science and Technology, University of South China, Hengyang, Hunan, 421001, China.
J Environ Radioact. 2021 Sep;235-236:106653. doi: 10.1016/j.jenvrad.2021.106653. Epub 2021 May 26.
The unattached fraction of Rn progeny is one of the key parameters in lung dose evaluation models. To study the behavior of unattached Rn progeny and to prepare for calibration of the unattached Rn progeny monitors, a Rn progeny chamber that could stably regulate different unattached fractions of Rn progeny was established. A recirculation loop to eliminate the effects of the sampling and a loop connected to the dilution chamber to supplement the carrier aerosol were set up. Also, a theoretical model regarding the regulation of the unattached fraction of Rn progeny was established. Continuous measurements of the unattached fraction were conducted using the combination of a single-layer wire screen and a filter membrane. The experimental results showed that, under different aerosol levels, the relative standard deviation (RSD) of Pb concentration during the continuous samplings was within 10.7% and the RSD of the unattached fraction of Pb was within 9.9%. The relative deviation between the theoretical and the experimental values of Pb concentration was within 16.7% and the model calculation values of the unattached fraction of Pb were consistent with measured results.
Rn 子体的非结合部分是肺部剂量评价模型中的关键参数之一。为了研究非结合 Rn 子体的行为并为非结合 Rn 子体监测器的校准做准备，建立了一个能够稳定调节不同 Rn 子体非结合部分的 Rn 子体室。建立了一个再循环回路以消除采样的影响，以及一个与稀释室相连的回路以补充载气气溶胶。此外，还建立了一个关于 Rn 子体非结合部分调节的理论模型。使用单层金属丝筛和滤膜的组合进行了非结合部分的连续测量。实验结果表明，在不同的气溶胶水平下，连续采样过程中 Pb 浓度的相对标准偏差（RSD）在 10.7%以内，Pb 的非结合部分的 RSD 在 9.9%以内。Pb 浓度的理论值和实验值之间的相对偏差在 16.7%以内，Pb 的非结合部分的模型计算值与实测结果一致。
