title: Estimation of radon diffusion coefficients in soil using an updated experimental system.
abstract: Radon diffusion through soil is strongly affected by the degree of water saturation of the soil pores. Methods have been developed by many researchers to measure radon diffusion coefficient. We developed an updated experimental system to estimate radon diffusion coefficients for typical types of soil in Japan and applied it to a typical loam with different water saturation levels (0-0.82). The system consists of a passive-type scintillation cell, soil column, accumulation tank, and radon source. The radon concentration in the accumulation tank is kept stable, and radon diffused through the soil column is continuously measured with the passive-type scintillation cell. We found the radon diffusion coefficients vary from 9.60 × 10(-6) m(2) s(-1) to 1.27 × 10(-7) m(2) s(-1) for the loam samples. Generally, the diffusion coefficients are almost constant for a water saturation range of 0-0.4 and decrease with increasing water saturation from 0.4 to 0.82.
authors.affiliation: National Institute of Radiological Sciences, 4-9-1 Anagawa, Chiba-shi, Chiba 263-8555, Japan.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Prasad
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hosoda
authors.forename: Atsuyuki
authors.initials: A
authors.lastname: Sorimachi
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Janik
authors.forename: Sarata Kumar
authors.initials: SK
authors.lastname: Sahoo
authors.forename: Shinji
authors.initials: S
authors.lastname: Tokonami
authors.forename: Shigeo
authors.initials: S
authors.lastname: Uchida
mesh_terms: D004058:Diffusion; D011874:Radiometry / Q000295:instrumentation*; D011886:Radon / Q000032:analysis* / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000032:analysis
chemical_list: D012987:Soil; D014867:Water; D011886:Radon