Al_2O_3纯化闪烁液过程中的放射性污染

Radioactive Contamination in the Purifying Process of Liquid Scintillator Using Al_2O_3 Particles

Al_2O_3可用于纯化闪烁液,但在纯化过程中有可能引入放射性污染。本工作对Al_2O_3纯化闪烁液过程中氡及Al_2O_3本身放射性对闪烁液的污染问题进行了研究。研究结果表明:通过Al_2O_3与闪烁液的混合澄清实验,发现若有细小Al_2O_3颗粒悬浮于闪烁液中会对闪烁液产生污染。但经过滤实验,发现过滤纯化闪烁液过程中的放射性污染主要来源于环境空气中氡的溶解,Al_2O_3过滤柱能阻挡绝大部分Al_2O_3中的放射性核素随着极细颗粒进入闪烁液。排除氡的影响后,在标准偏差范围内,未过滤与经Al_2O_3过滤后的闪烁液的放射性计数率无明显变化,说明Al_2O_3样品中的放射性对闪烁液的影响已低于液闪的探测灵敏度。

Al2O3 can be used for the purification of liquid scintillator,but radioactive contamination may happen in the process of purification.Radioactive contamination of liquid scintillator in the process of purification is studied in this paper.Research shows that when the Al2O3 was mixed with liquid scintillator,the supernatant liquid scintillator can be contaminated by radioactive impurities in the suspended Al2O3 .The results of liquid scintillator filtration experiments with Al2O3 filter column show that contamination of liquid scintillator may come from the radon in air.The Al2O3 filter column can prevent most of the radioactive impurities from flowing into the liquid scintillator with fine Al2O3 particles.After the removal of the influence of radon,there is no significant difference in radioactivity between filtered liquid scintillator and unfiltered liquid scintillator in the range of standard deviation.In other words,the radioactive contamination of liquid scintillator from Al2O3 is below detectionsensitivity of liquid scintillation counter.