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. (authors)