低本底条件下氡及其子体的抑制研究

Study on the inhibition of radon and its daughters under low background conditions

摘要:

稀有事例的探测中需要极低的本底，氡及其子体是主要的本底来源之一. 文章依据地下实验室1 725 m³液氮除氡需求，设计了一套液氮除氡系统，初步测试了KC-6系列活性炭在-10~-120 ℃下的除氡效果. 实验结果表明，误差函数能很好的拟合活性炭在不同温度下的穿透曲线. 拟合数据表明在-10和-30 ℃下活性炭对氡的动力学吸附系数分别为23.01 ± 0.33和58.68 ± 0.63 L/g. 有限的数据表明在-120 ℃下没有氡溢出，但是可以算出此时的动力学吸附系数已经大于432 L/g. 文章中所得到的数据将为低放射本底液氮中氡的去除研究奠定基础.

Abstract:

The detection of rare cases requires a very low background, and radon and its daughters are one of the main background sources. In this paper, a set of liquid nitrogen radon removal system was designed according to the demand for radon removal of 1 725 m³ liquid nitrogen in the underground laboratory, and the radon removal effect of KC-6 series activated carbon was preliminarily tested at -10~ -120 ℃. Experimental results show that the error function can well fit the penetration curve of activated carbon at different temperatures. The fitted data shows that the dynamic adsorption coefficients of radon on activated carbon at -10 and -30 ℃ are 23.01 ± 0.33 and 58.68 ± 0.63 L/g, respectively. Limited data indicate that there is no radon overflow at -120 ℃. However, it can be calculated that the dynamic adsorption coefficient is already greater than 432 L/g. The data obtained in this paper could lay a foundation for the study of radon removal from low emission background liquid nitrogen.