量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果(学会誌発表論文、学会発表、研究開発報告書、特許等)を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum Science and Technology.
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A solid 222Rn (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 226Ra and the sintering temperature. A 226Ra sulfate (226RaSO4) 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 226Ra 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 226Ra 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 226Ra and its decay products. Such advantages in a radon generation system are desirable for experiments of high-level, large-scale radon exposure.