In this study, we propose a new method for elucidating zircon growth in granitic plutons, based on the variations in three-dimensional (3D) cathodoluminescence (CL) patterns, U[sbnd]Pb age, titanium concentration, and Th/U. We focused on the zirco...
Ami Yoshida   Junko Shikimori   Takeshi Ohno   Yuta Ijichi   Yusuke Fukami   Masahiro Sakata   Takafumi Hirata   
Journal of environmental radioactivity 255 107011-107011 2022年9月 [査読有り]
We examine the historical changes of 236U/238U and 235U/238U in a sediment core collected in Tokyo Bay and elucidate the anthropogenic sources of uranium in the 1960s-2000s. Uranium-236 was detected in samples deposited in the 1960s-2000s, and the...
Hiroyuki Matsuzaki   Yasuyuki Muramatsu   Takeshi Ohno   Wei Mao   
EPJ Web of Conferences 153 2017年9月
Iodine-131 distribution released from the Fukushima Dai-ichi Nuclear Power Plant accident was reconstructed through the iodine-129 measurements. From nearly 1,000 surface soil samples iodine was extracted by the pyro hydrolysis method. Extracted i...
<p>半減期1570万年である放射性ヨウ素-129は放射性ヨウ素の環境トレーサーとして用いられてきた。環境試料中のヨウ素-129の濃度を迅速に調べる手法の一つとして、溶液試料導入法を用いたICP質量分析計による測定法が提案されている(Ohno et al., 2013)。しかしこの手法では、127Iの水素化物イオンによる質量数129への干渉を完全には除去できず、測定の感度も十分とは言えないという問題点がある。そこで本研究では試料溶液中のヨウ素を酸化気化しICP質量分析...