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  2. 石田 章純

石田 章純

イシダ アキズミ  (Akizumi Ishida)

基本情報

所属
千葉大学 大学院理学研究院 融合理工学府 地球科学コース 准教授 (博士)
学位
博士 (理学)(2012年3月 東北大学)
J-GLOBAL ID
201201082579344652
researchmap会員ID
7000002186

研究キーワード

 11

研究分野

 3

経歴

 7
もっとみる

学歴

 3

論文

 40
  • Kohei Sasaki, Akizumi Ishida, Takeshi Kakegawa, Naoto Takahata, Yuji Sano
    Scientific Reports 14(1) 2024年9月20日  
  • Ko Hashizume, Akizumi Ishida, Ayano Chiba, Ryuji Okazaki, Kasumi Yogata, Toru Yada, Fumio Kitajima, Hisayoshi Yurimoto, Tomoki Nakamura, Takaaki Noguchi, Hikaru Yabuta, Hiroshi Naraoka, Yoshinori Takano, Kanako Sakamoto, Shogo Tachibana, Masahiro Nishimura, Aiko Nakato, Akiko Miyazaki, Masanao Abe, Tatsuaki Okada, Tomohiro Usui, Makoto Yoshikawa, Takanao Saiki, Fuyuto Terui, Satoshi Tanaka, Satoru Nakazawa, Sei‐ichiro Watanabe, Yuichi Tsuda, Michael W. Broadley, Henner Busemann
    Meteoritics & Planetary Science 2024年4月30日  
    Abstract The nitrogen isotope compositions of two samples returned from the asteroid Ryugu were determined using a stepwise combustion method, along with Ivuna (CI) and Y‐980115, a CI‐like Antarctic meteorite, as references. The two Ryugu samples A0105‐07 and C0106‐07 showed bulk δ15N values of +1.7 ± 0.5‰ and +0.2 ± 0.6‰, respectively, significantly lower than Ivuna with +36.4 ± 0.4‰, but close to Y‐980115 with +4.0 ± 0.3‰. The Ryugu samples are further characterized by C/N and 36Ar/N ratios up to 3.4× and 4.9× the value of Ivuna, respectively. Among all Ryugu samples and CI chondrites, a positive correlation was observed between nitrogen concentrations and δ15N values, with samples with lower nitrogen concentrations exhibiting lower δ15N. This trend is explained by a two‐component mixing model. One component is present at a constant abundance among all CI‐related samples, with a δ15N value around 0‰ or lower. The other varies in abundance between different samples, and exhibits a δ15N value of +56 ± 4‰. The first 15N‐poor endmember is seemingly tightly incorporated into a carbonaceous host phase, whereas the 15N‐rich endmember can be mobilized and decoupled from carbon, potentially because it is in the form of ammonia. Asteroid materials with volatile compositions that are similar to those reported here for the Ryugu samples are attractive candidates for the volatile sources among Earth's building blocks.
  • Akizumi Ishida, Kouki Kitajima, Ko Hashizume, Michael J. J. Spicuzza, Alexander Zaitsev, Daniel J. J. Schulze, John W. W. Valley
    GEOSTANDARDS AND GEOANALYTICAL RESEARCH 2023年4月  
    Simultaneous analysis of carbon and nitrogen isotope ratios by SIMS was applied for the first-time to a natural diamond from the Kelsey Lake kimberlite, State Line Distinct, Colorado (UWD-1). This in situ procedure is faster, reduces sample size for analysis, and measures both isotope ratios from a single similar to 10 mu m diameter pit, a critical advantage for zoned diamonds. The carbon isotope ratio (expressed as delta C-13(VPDB)) of the bulk UWD-1 crystal, determined by the conventional combustion method in the present study, is -5.9 parts per thousand +/- 0.2 parts per thousand (VPDB, 2s). Nitrogen mass fraction ([N]) and isotope ratio (expressed as delta N-15(Air)) were determined by stepwise combustion and gas-source mass-spectrometry, resulting in 553 +/- 64 mu g g(-1) and -6.7 parts per thousand +/- 1.1 parts per thousand (Air, 2s), respectively. Secondary ions of C-12(2)-, (CC-)-C-12-C-13, (CN-)-C-12-N-14, and (CN-)-C-12-N-15 were simultaneously measured by SIMS using three Faraday cups and one electron multiplier. The spot-to-spot reproducibility of delta C-13 and delta N-15 values for the UWD-1 (178 spots on sixteen chips, 10 mu m spots), were 0.3 parts per thousand and 1.6 parts per thousand, respectively (2s). While (CN-)-C-12-N-14/C-12(2)- ratios, which are an indicator for [N], varied up to 12% among these sixteen chips, such variation did not correlate with either delta C-13 or delta N-15 values. We propose that UWD-1 is a suitable reference sample for microscale in situ analysis of delta C-13 and delta N-15 values in diamond samples.
  • Ryuji Okazaki, Yayoi N Miura, Yoshinori Takano, Hirotaka Sawada, Kanako Sakamoto, Toru Yada, Keita Yamada, Shinsuke Kawagucci, Yohei Matsui, Ko Hashizume, Akizumi Ishida, Michael W Broadley, Bernard Marty, David Byrne, Evelyn Füri, Alex Meshik, Olga Pravdivtseva, Henner Busemann, My E I Riebe, Jamie Gilmour, Jisun Park, Ken-Ichi Bajo, Kevin Righter, Saburo Sakai, Shun Sekimoto, Fumio Kitajima, Sarah A Crowther, Naoyoshi Iwata, Naoki Shirai, Mitsuru Ebihara, Reika Yokochi, Kunihiko Nishiizumi, Keisuke Nagao, Jong Ik Lee, Patricia Clay, Akihiro Kano, Marc W Caffee, Ryu Uemura, Makoto Inagaki, Daniela Krietsch, Colin Maden, Mizuki Yamamoto, Lydia Fawcett, Thomas Lawton, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Hikaru Yabuta, Hisayoshi Yurimoto, Yuichi Tsuda, Sei-Ichiro Watanabe, Masanao Abe, Masahiko Arakawa, Atsushi Fujii, Masahiko Hayakawa, Naoyuki Hirata, Naru Hirata, Rie Honda, Chikatoshi Honda, Satoshi Hosoda, Yu-Ichi Iijima, Hitoshi Ikeda, Masateru Ishiguro, Yoshiaki Ishihara, Takahiro Iwata, Kosuke Kawahara, Shota Kikuchi, Kohei Kitazato, Koji Matsumoto, Moe Matsuoka, Tatsuhiro Michikami, Yuya Mimasu, Akira Miura, Tomokatsu Morota, Satoru Nakazawa, Noriyuki Namiki, Hirotomo Noda, Rina Noguchi, Naoko Ogawa, Kazunori Ogawa, Tatsuaki Okada, Chisato Okamoto, Go Ono, Masanobu Ozaki, Takanao Saiki, Naoya Sakatani, Hiroki Senshu, Yuri Shimaki, Kei Shirai, Seiji Sugita, Yuto Takei, Hiroshi Takeuchi, Satoshi Tanaka, Eri Tatsumi, Fuyuto Terui, Ryudo Tsukizaki, Koji Wada, Manabu Yamada, Tetsuya Yamada, Yukio Yamamoto, Hajime Yano, Yasuhiro Yokota, Keisuke Yoshihara, Makoto Yoshikawa, Kent Yoshikawa, Shizuho Furuya, Kentaro Hatakeda, Tasuku Hayashi, Yuya Hitomi, Kazuya Kumagai, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Hiromichi Soejima, Ayako Iwamae, Daiki Yamamoto, Kasumi Yogata, Miwa Yoshitake, Ryota Fukai, Tomohiro Usui, Trevor Ireland, Harold C Connolly Jr, Dante S Lauretta, Shogo Tachibana
    Science advances 8(46) eabo7239 2022年11月18日  
    The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on 6 December 2020. One day after the recovery, the gas species retained in the sample container were extracted and measured on-site and stored in gas collection bottles. The container gas consists of helium and neon with an extraterrestrial 3He/4He and 20Ne/22Ne ratios, along with some contaminant terrestrial atmospheric gases. A mixture of solar and Earth's atmospheric gas is the best explanation for the container gas composition. Fragmentation of Ryugu grains within the sample container is discussed on the basis of the estimated amount of indigenous He and the size distribution of the recovered Ryugu grains. This is the first successful return of gas species from a near-Earth asteroid.
  • Ryuji Okazaki, Bernard Marty, Henner Busemann, Ko Hashizume, Jamie D Gilmour, Alex Meshik, Toru Yada, Fumio Kitajima, Michael W Broadley, David Byrne, Evelyn Füri, My E I Riebe, Daniela Krietsch, Colin Maden, Akizumi Ishida, Patricia Clay, Sarah A Crowther, Lydia Fawcett, Thomas Lawton, Olga Pravdivtseva, Yayoi N Miura, Jisun Park, Ken-Ichi Bajo, Yoshinori Takano, Keita Yamada, Shinsuke Kawagucci, Yohei Matsui, Mizuki Yamamoto, Kevin Righter, Saburo Sakai, Naoyoshi Iwata, Naoki Shirai, Shun Sekimoto, Makoto Inagaki, Mitsuru Ebihara, Reika Yokochi, Kunihiko Nishiizumi, Keisuke Nagao, Jong Ik Lee, Akihiro Kano, Marc W Caffee, Ryu Uemura, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Hikaru Yabuta, Hisayoshi Yurimoto, Shogo Tachibana, Hirotaka Sawada, Kanako Sakamoto, Masanao Abe, Masahiko Arakawa, Atsushi Fujii, Masahiko Hayakawa, Naoyuki Hirata, Naru Hirata, Rie Honda, Chikatoshi Honda, Satoshi Hosoda, Yu-Ichi Iijima, Hitoshi Ikeda, Masateru Ishiguro, Yoshiaki Ishihara, Takahiro Iwata, Kosuke Kawahara, Shota Kikuchi, Kohei Kitazato, Koji Matsumoto, Moe Matsuoka, Tatsuhiro Michikami, Yuya Mimasu, Akira Miura, Tomokatsu Morota, Satoru Nakazawa, Noriyuki Namiki, Hirotomo Noda, Rina Noguchi, Naoko Ogawa, Kazunori Ogawa, Tatsuaki Okada, Chisato Okamoto, Go Ono, Masanobu Ozaki, Takanao Saiki, Naoya Sakatani, Hiroki Senshu, Yuri Shimaki, Kei Shirai, Seiji Sugita, Yuto Takei, Hiroshi Takeuchi, Satoshi Tanaka, Eri Tatsumi, Fuyuto Terui, Ryudo Tsukizaki, Koji Wada, Manabu Yamada, Tetsuya Yamada, Yukio Yamamoto, Hajime Yano, Yasuhiro Yokota, Keisuke Yoshihara, Makoto Yoshikawa, Kent Yoshikawa, Shizuho Furuya, Kentaro Hatakeda, Tasuku Hayashi, Yuya Hitomi, Kazuya Kumagai, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Hiromichi Soejima, Ayako Iwamae, Daiki Yamamoto, Kasumi Yogata, Miwa Yoshitake, Ryota Fukai, Tomohiro Usui, Harold C Connolly Jr, Dante Lauretta, Sei-Ichiro Watanabe, Yuichi Tsuda
    Science (New York, N.Y.) 379(6634) eabo0431 2022年10月20日  
    The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measure noble gas and nitrogen isotopes in Ryugu samples, finding they are dominated by pre-solar and primordial components, incorporated during Solar System formation. Noble gas concentrations are higher than those in Ivuna-type carbonaceous (CI) chondrite meteorites. Several host phases of isotopically distinct nitrogen have heterogeneous abundances between the samples. Our measurements support a close relationship between Ryugu and CI chondrites. Noble gases produced by galactic cosmic rays, indicating ~5 Myr exposure, and from implanted solar wind, record the recent irradiation history of Ryugu after it migrated to its current orbit.
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 5

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