広島県東部地区の自然環境ガンマ線による空気カーマ率の測定 (I)
芦田川水系を中心として
1998 年 33 巻 4 号 p. 429-434
詳細
1998 年 33 巻 4 号 p. 429-434
Air kerma rates in the basin of the Ashida River of Hiroshima Prefecture were measured by a NaI (Tl) scintillation spectrometer. It was found that they were distributed from 5.4×101nGy h-1 to 1.2×102nGy h-1 and had a mean value of (7.9±1.8)×101nGy h-1, which was about 30% higher than the air-absorbed dose rates determined by the National Institute of Radiological Science. It also became clear from a comparison of gamma-ray spectra measured there that two kinds of parent rocks whose components of radionuclides were very much different from each other would be the sources of the gamma ray exposure in this area.
