title: Development of radon sources with a high stability and a wide range.
abstract: A solid (222)Rn (radon) source using a fibrous and porous SiC ceramic disk was developed. The emission rate of radon emanated from the disk depended on the content of (226)Ra and the sintering temperature. A (226)Ra sulfate ((226)RaSO4) solution was dropped on a fibrous SiC ceramic disk (33 mmφ) of 1 mm in thickness, and sintered at 400 °C. The radon concentration from a disk containing (226)Ra of 1.85 MBq was measured to be 38 kBq m(-3) at a carrier airflow rate of 0.5 L min(-1). By adjusting the (226)Ra content or the sweep airflow rate, the radon concentrations were easily controlled over a wide range of over three orders of magnitude. The concentration was very stable for a long term. The compactness of the source disk made is easy for handling the source container and the shielding of gamma radiation from (226)Ra and its decay products. Such advantages in a radon generation system are desirable for experiments of high-level, large-scale radon exposure.
authors.affiliation: National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukutsu
authors.affiliation: National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada