著者

Shichijo Kazuko Takatsuji Toshihiro Yamamoto Masayoshi Nakashima Masahiro

出版者

広島大学平和科学研究センター

雑誌

IPSHU English Research Report Series

巻号頁・発行日

no.28, pp.70-73, 2012-03

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The explosion of a plutonium Atomic bomb over Nagasaki city in Japan took place at 1102h on August 9, 1945. Radiation dose of A-bomb survivor is practically estimated from external radiation. The alpha particles can be disregarded science they travel only a short distance through air. Plutonium remaining in the soil at Nagasaki after 24yr has been determined in 1971. In the patients subjected to the Atomic bomb there was no evidence of the introduction of radioactive material. We have already studied the preserved body cells of seven A-bombed victims in 1945, and became the first one to prove that plutonium is continuing to emit radiations after more than 60 years since the A-bomb attack. In this study, the nuclide identification of alpha-emitters in environmental samples and calibration standards has been attempted by the measurement of the alpha track length using autoradiography. Alpha track length in Nagasaki soil; Ground surface soil collected in 1979 from the Nishiyama area in Nagasaki City, 210Po, 241Am and 243Am fitted the relation curve between energy and track length of alpha-particles in the photo emulsion. Moreover, the alpha track length in Nagasaki soil was consisted with that in paraffin-embedded specimen of A-bomb cases. Therefore, the nuclide of alpha-emitters in specimen of atomic victims at Nagasaki was identified with 239,240Pu by autoradiography.