Abstract Pinhole-based twin cup dosimeters are capable of distinguishing 222Rn and 220Rn passively, as well as measuring their concentrations via Solid State Nuclear Track Detector films. However, the reliability of the measurements can be affected by environmental conditions and design of the device. To evaluate the significance of diffusion coefficient of air, radius, length, and number of pinholes, as well as radius and length of the twin cups on the effectiveness of the device, computational fluid dynamics models were developed for 14 scenarios. Concentration distributions of 222Rn and 220Rn were obtained, with their transmission factors each calculated and compared for the twin cups and for the pinhole(s). The results suggest that little to no impact was made on 222Rn's transmission factors, despite the change in diffusion coefficient and dimensions of the pin hole and the twin cup. However, for 220Rn, transmission factors significantly increased with an increase in pinhole radius, number of holes, or diffusion coefficient, or a decrease in pinhole length, twin cup length, or twin cup radius.

中文翻译：

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使用计算流体动力学模拟评估 222Rn 和 220Rn 区分浓度测量的针孔双杯剂量计

摘要 基于针孔的双杯剂量计能够被动区分 222Rn 和 220Rn，并通过固态核径迹探测器薄膜测量它们的浓度。然而，测量的可靠性会受到环境条件和设备设计的影响。为了评估空气的扩散系数、半径、长度和针孔数量，以及双杯的半径和长度对装置有效性的重要性，我们针对 14 种情况开发了计算流体动力学模型。获得了 222Rn 和 220Rn 的浓度分布，分别计算并比较了双杯和针孔的透射系数。结果表明，对 222Rn 的传输因子几乎没有影响，尽管针孔和双杯的扩散系数和尺寸发生了变化。然而，对于 220Rn，透射系数随着针孔半径、孔数或扩散系数的增加，或针孔长度、双杯长度或双杯半径的减小而显着增加。