低射气介质地区浅部土壤氡气迁移规律研究

以内蒙古乌兰察布低放射性地区所测氡浓度作为分析对象，运用分形理论，提出了氡浓度分形分析法，得到在坑深30～60 cm范围内氡浓度分布的分形规律和分形维数。结果表明，不同坑深下，氡气分布具有很强的自相似性，符合分形规律，且分形维数在坑深40 cm左右达最小值。氡气浓度均值变化系数定量地表征了不同坑深下氡浓度变异程度，得出坑深40 cm左右变化率最小，分布相对稳定。两种方法相结合表明，野外测氡时，坑深取40 cm效果较好。

Research on Radon Migration Rules in Shallow Soil of Low Radioactive Containing Material

Taking field measuring radon concentration in Ulanchap, China as the analytical objects, radon concentration fractal method was proposed with adopting fractal theory, and the fractal laws and the fractal dimensions for the distribution laws of radon concentration were obtained within the depth range from 30 cm to 60 cm. The results indicate that the radon distribution has strong self-similarity according to fractal laws and the minimum value of fractal dimensions is reached at the depth of 40 cm. The factor of mean value difference quantitatively expressed the extent of variation for radon concentration under different depths, and the same result with radon fractal measuring method was got. Two methods show that the best buried depth for field radon equipment is 40 cm.