单层丝网法氡子体未结合态份额测量中结合态氡子体的影响评估

为系统研究单层丝网法测量氡子体未结合态份额中结合态氡子体的影响，本研究基于理论分析和实验测量，评估了同一种环境下不同目数的丝网对结合态氡子体的收集效率，分析了同一种丝网应用于不同的环境测量时结合态氡子体对未结合态份额测量的影响。研究表明，不同目数的金属丝网对结合态氡子体的收集效率并不高（0.7%～1.0%），但由于典型室内环境中结合态氡子体占比较高（～92%），结合态氡子体的存在会导致氡子体未结合态份额的测量值出现一定的系统性正偏差（3.1%～9.5%），且该系统性正偏差随丝网目数的增加而增加。同一目数丝网，从室内环境直接应用于室外、矿山环境时，由于结合态氡子体中粗粒子模态占比较高，导致氡子体未结合态份额测量值出现较大偏差。从理论计算结果看，典型室外、矿山环境的偏差分别达40.3%和113%，这说明在使用单层丝网法测量氡子体未结合态份额时，有必要针对不同环境对金属丝网进行优选，尽量减少氡子体未结合态份额测量偏差。

Evaluation on Influence of Attached Radon Progeny on Measurement of Unattached Fraction of Radon Progeny with Single Screen Method

In order to systematically study the influence of attached radon progeny, the collection efficiency of attached radon progeny by different screens in the same environment was evaluated based on theoretical analysis and experimental measurement, and the influence of attached radon progeny was analyzed when the same screen was used in different environments. The results show that the single screen with different mesh numbers have lower collection efficiency (0.7%-1.0%) for attached radon progeny. However, due to the high fraction of attached radon progeny (about 92%) in typical indoor environment, the measured value of the unattached fraction of radon progeny has a systematic positive deviation (3.1%-9.5%). This systematic positive deviation increases with the grading of screen mesh number. When the same screen is directly applied to outdoor and mine environment from indoor environment, the coarse particle mode radon progeny will cause large deviation in the measured result of unattached fraction of radon progeny. The theoretical calculation results show that the deviation calculation values of typical outdoor and mine environment was 40.3% and 113% respectively, which indicates that it is necessary to optimize the screen in different environments to reduce the measurement deviation of the unattached fraction of radon progeny.