水中总α、总β放射性测量方法探究

Study on experimental methods of total α and total β radioactivity in water

利用低本底α、β测量仪研究影响水中总α、β放射性活度浓度测量的实验因素。通过一系列对比实验,获得样品放置时间、水样的贮存时间和贮存温度、样品制备方式等条件对实验结果的影响。结果表明:井水、自来水、地下水等水体内溶解的氡和红外线加热可能对水样残渣的计数产生干扰,样品制备完毕后,宜在室温且干燥环境下静置至少3小时后再进行上机测量;水样在密封贮存的情况下,贮存温度和时间对水样的总α、总β放射性活度无显著影响;采用现行国标推荐的硫酸酸化水样的方法可以有效避免样品可能存在的吸潮现象,减少实验误差。

Experimental methods of total α and total β radioactivity in water using low-background α and β measuring system are discussed in this article.Based on a series of comparative experiments,the storage time and temperature of samples,sample preparation method and placement time,which may influence the experimental results,are put forward to reduce the experimental uncertainties.Radon dissolved in water such as well water,tap water and groundwater or infrared lamp may interfere with the counting.After the sample preparation,it is advisable to put the sample at room temperature and dry environment for at least 3 hours before measurement.It shows that storage temperature and storage time have no significant effects on total α and total β radioactivity of water under the condition of sealed storage.Furthermore,acidification of water samples with sulfuric acid recommended by the current national standard,can effectively avoid moisture absorption so as to reduce experimental uncertainty.