Electron-capture decay rate of 7Be encapsulated in fullerene cages

• Project/Area Number: 23600001
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Quantum beam science
• Research Institution: Kyoto University (2013-2014); Tohoku University (2011-2012)
• Principal Investigator: OHTSUKI Tsutomu 京都大学, 原子炉実験所, 教授 (50233193)
• Co-Investigator(Kenkyū-buntansha): 菊永 英寿 東北大学, 学内共同利用施設等, 准教授 (00435645)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2011: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: 半減期 / 放射性ベリリウム / フラーレン / 自動測定 / 崩壊定数 / 放射性金属ベリリウム / 自動測定装置 / 半減期変化 / フッ化物

Outline of Final Research Achievements

The decay rate of Be-7 electron capture (EC) was measured in C60 and C70 and Be metal with a reference method. The half-life of 7Be endohedral C60, C70 (7Be@C60,C70) was found to be 52.49±0.04 days for He temperature. These values are almost 1.5% shorter than that of Be-7 in Be metal at room temperature. The result is a reflection of the different electron wave-functions for Be-7 inside C60, C70 compared to when Be-7 is in Be metal. The magnitude of the average charge-transfer from the L(2s) electrons of the Be-7 atom play an important role in such variation in the decay constant in the environments.

Research Products

• [Journal Article] Comparison of the decay constants of 51Cr with metal, oxide, and chromate chemical states (2015)
  • Author(s): H. Kikunaga , K. Takamiya, K. Hirose, T. Ohtsuki
  • Journal Title: Journal of Radioanalytical and Nuclear Chemistry Volume: 303 Pages: 1581-1583
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] C60中のEC崩壊核種Be-7の半減期とその化学的環境 (2015)
  • Author(s): 大槻勤
  • Journal Title: 三菱財団研究事業報告書2014 Volume: 1 Pages: 1-8
• [Journal Article] Study for Heavy-Ion Induced Fission for the Heavy Element Synthesis. (2014)
  • Author(s): K. Nishio, H. Ikezoe, H. Makii, S. Mitsuoka, Y. Nagame, I. Nishinaka, Ackermann, V.F. Comas, Heinz, J.A. Heredia, J. Khuyagbaatar, I. Kojouharov, B. Lommel, R. Mann Y. Aritomo, A.G. Popeko, A.V. Yeremin, Y. Wakabayashi, S. Antalic, S. Saro, Bratislava, Slovakia. K. Hirose, T. Ohtsuki, Y. Watanabe, K. Hagino
  • Journal Title: EPJ Web of Conferences Volume: 66 Pages: 03065-03065
  • Peer Reviewed / Open Access
• [Journal Article] Corprecipitation Behavieor of Zr, Hf, and Th with Sm Hydroxide for Chemical Study of Element 104, Rf. (2014)
  • Author(s): Y. Kasamatsu,K. Toyomura, N. Shiohara,T. Yokokita, Y. Komori, A. Kino, T. Yoshimura, N. Takahashi, H. Haba, Y. Kudou, H. Kikunaga, T. Mitsugashira, T. Ohtsuki, K. Takamiya, A. Shinohara
  • Journal Title: Journal of Nuclear and Radiochemical Sciences Volume: 14 Pages: 299-302
  • Peer Reviewed / Open Access
• [Journal Article] Study of Heavy-ion Induced Fission for Heavy Element Synthesis (2014)
  • Author(s): K. Nishio, H. Ikezoe, S. Hofmann, Y. Aritomo, V.F. Comas, S. Heinz, J.A. Heredia, F.P. Hesberger, K. Hirose, J. Khuyagbaatar, B. Kindler, I. Kojouharov, B. Lommel, M. Makii, R. Mann, S. Mitsuoka, I. Nishinaka, T. Ohtsuki, S. Saro, M. Sch¨adel, A.G. Popeko, A. T¨urler, Y. Wakabayashi, Y. Watanabe, A. Yakushev
  • Journal Title: Nuclear Data Sheets Volume: 119 Pages: 299-302
  • NAID: 120005820902
  • Peer Reviewed / Open Access
• [Journal Article] Surrogate Reactions Research at JAEA/Tokyo Tech. (2014)
  • Author(s): S. Chiba, K. Nishio, H. Makii, Y. Aritomo, I. Nishinaka, T. Ishii, K. Tsukada, M. Asai, K. Furutaka, S. Hashimoto, H. Koura, K. Ogata, T. Ohtsuki, and T. Nagayama
  • Journal Title: Nuclear Data Sheets Volume: 119 Pages: 229-232
  • Peer Reviewed
• [Journal Article] Comparison of the decay constants of Cr-51 metal, oxide, and chromate chemical states. (2014)
  • Author(s): H.Kikunaga, K.Takamiya, K. Hirose, T. Ohtsuki
  • Journal Title: Jornal of Radio and Nuclear Chemistry Volume: 印刷中
  • Peer Reviewed
• [Presentation] HALF-LIFE MEASUREMENTS OF BERYLLIUM-7 IN MATERIALS (2015)
  • Author(s): T. Ohtsuki
  • Organizer: Tenth International Conference on Methods and Applications of Radioanalytical Chemistry
  • Place of Presentation: Sheraton, Kona Keauhou Resort, Hawaii
  • Year and Date: 2015-04-12 – 2015-04-17
• [Presentation] Half-life measurement of Be-7 in materials (2014)
  • Author(s): T. Ohtsuki
  • Organizer: Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan
  • Place of Presentation: Hilton, Waikoloa, Hawaii
  • Year and Date: 2014-10-07 – 2014-10-11
• [Presentation] Half-life measurement of 7Be in materials (2014)
  • Author(s): T. Ohtsuki
  • Organizer: Fifth Symposium on Nuclear Analytycal Chemistry
  • Place of Presentation: Bhabha Atomic Research Centre, Trombay, Mumbai, India
  • Invited
• [Presentation] Half-life measurement of 7Be in several materials (2013)
  • Author(s): T. Ohtsuki
  • Organizer: 5th Asia-Pacific Symposium on Radiochemistry（APSORC13）
  • Place of Presentation: Kanazawa Bunka Hall, Kanazawa