The precise measurement of electron capture decay rate of ^7Be encapsulated in C_<60>

C_<60>封装^7Be电子俘获衰减率的精确测量

• 批准号: 17350024
• 负责人: OHTSUKI Tsutomu
• 金额: $ 9.89万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17350024/
• 关键词: Half-life; Electron capture decay; Fullerene; Beryllium; Vacuum; 半減期変化; 比較自動測定

The electron capture (EC) decay rate of ^7Be in C_<60> at the temperature of liquid helium (T=5K) was measured and compared with the rate in Be metal at T=293K. We found that the half-life of ^7Be in endohedral C_<60>(^7Be@C_<60>) at a temperature close to T=5K is 52.47±0.04 days, a value that is 0.34% faster than that at T=293K. In this environment, the half-life of ^7Be is nearly 1.5% faster than that inside Be metal at room temperature (T=293K). We then interpreted our observations in terms of calculations of the electron density at the ^7Be nucleus position inside the C_<60>; further, we estimate theoretically the temperature dependence (at T=0K and 293K) of the electron density at the Be nucleus position in the stable center inside C_<60>. The theoretical estimates were almost in agreement with the experimental observations.

在液氦温度（T=5K）下，测量了C_<60>中^7Be的电子俘获（EC）衰变速率，并与金属Be在T=293K时的速率进行了比较。我们发现^7Be在接近T=5K时的半衰期为52.47±0.04天，比T=293K时的半衰期缩短了0.34%。在这种环境下，^7Be的半衰期比室温（T=293K）下Be金属内部的半衰期快了近1.5%。然后，我们根据C_<60>内^7Be核位置的电子密度计算来解释我们的观察结果；进一步，我们从理论上估计了C_<60>内稳定中心Be核位置的电子密度与温度的关系（T=0K和293K）。理论估计与实验观察几乎一致。

项目成果

Electron-Capture Decay Rate of 7^Be Encapsulated in C_60 Cages

封装在 C_60 笼中的 7^Be 电子捕获衰变率

• 发表时间: 2007
• 期刊: J. Nucl. Radiochem. Sci. 8
• 作者: T;Ohtsuki;Jun Onoe;Erm Kikuch;Y.Kodama;H. Suzuki;T. Ohtsuki
• 通讯作者: T. Ohtsuki

「研究成果報告書概要(和文)」より

摘自《研究结果报告摘要（日文）》

• 发表时间: 2005
• 作者: Kawauchi;et. al.;Nishimura et al.;Dezawa et al.;Yoshizawa et al.;星野 幹雄;星野 幹雄
• 通讯作者: 星野 幹雄

Inside of C60 is magical space?! (Observation of nuclear decay influenced by orbital electrons)

C60内部有神奇空间？！

• 发表时间: 2007
• 期刊: KAGAKU 62, No11
• 作者: T. Ohtsuki ;et. al.;T. Ohtsuki et. al.;T. Ohtsuki et. al.;T. Ohtsuki et. al.
• 通讯作者: T. Ohtsuki et. al.

Radioactive decay speedup at T=5K: Electron-capture decay rate of Be-7 encapsulated in C-60

T=5K 时的放射性衰变加速：封装在 C-60 中的 Be-7 的电子捕获衰变率

• 发表时间: 2007
• 期刊: Physical Review Letters 98
• 作者: T. Ohtsuki ;et. al.;T. Ohtsuki et. al.
• 通讯作者: T. Ohtsuki et. al.

Radiochemical studies at the cyclotron laboratory Tohoku University

东北大学回旋加速器实验室的放射化学研究

• 发表时间: 2006
• 期刊: Czech Journal of Physics 56D
• 作者: T. Ohtsuki ;et. al.;T. Ohtsuki et. al.
• 通讯作者: T. Ohtsuki et. al.