活性炭吸附-液闪法测量建材氡析出率的研究

为实现建材样品氡析出率的自动化测量，本文研究了一种活性炭吸附-液闪测量建材氡析出率的方法，并通过比较活性炭吸附-液闪法与活性炭吸附-γ能谱法在氡析出率标准装置、铀矿砂水泥砖及发泡砖表面测量值之间的差异，验证该方法的准确性。测量结果表明：活性炭吸附 液闪法可在一定条件下忽略反扩散的影响；根据制备的C-LS-Rn标准源可得其刻度系数为72.36 min^-1?Bq^-1，对氡的计数效率为120%；累积时间为72 h的最小可探测氡析出率为8.15×10^-4 Bq/(m²?s)；该方法与活性炭吸附-γ能谱法测量结果的相对偏差为10%左右，在可接受范围内。

Research on Measurement of Radon Exhalation Rate in Building Material Using Active Carbon Adsorption-Liquid Scintillation Method

In order to achieve automatic measurement of radon exhalation rate in building materials, an active carbon adsorption-liquid scintillation method was introduced. By comparing the measurement results of this method with the active carbon absorption-γ energy spectrum method on the surfaces of the radon exhalation standard device, uranium ore brick and foaming, the accuracy of this method was verified. The results show that the active carbon adsorption-liquid scintillation method can ignore the effect of back-diffusion under certain conditions. Based on the C-LS-Rn standard source, the calibration coefficient of this method is 72.36 min^-1?Bq^-1. The counting efficiency of radon is 120% by this method. The minimum detectable radon exhalation rate is 8.15×10^-4 Bq/(m²?s) when cumulative time is 72 h. The relative deviation of measurement results between these two methods is about 10%, within the acceptable range.