Development of a new ^<227>Ac counter based on detection ^<219>Rn

基于检测^<219>Rn开发新的^<227>Ac计数器

• 批准号: 07554082
• 负责人: NOZAKI Yoshiyuki
• 金额: $ 0.9万
• 依托单位: Ocean Research Institute, University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07554082/
• 关键词: Actinium; Radon; alpha-scintillation cells; photomultipliers; conuting electronics; MnO_2 fiber; ラドン娘核種; マンガンファイバー; α線シンチレーション; フローシステム

Actinium-227 is a nuclide belong to the ^<235>U decay chain. It's half life (21.7 years) is comparable within that of ^<210>Pb(t_<1/2>=22.7y). Although ^<210>Pb is widely used as a dating tool of lar, coastal and shelf sediments and a tracer of heavy metals in the marine environments, application of ^<227>Ac geochemical problems is limited due to absence of convienient method of determination. The purpose of this study is to develop a new counting method which includes detection of short-lived radon (^<219>Rn and ^<220>Rn) and its decay products by alpha-scintillation cells.The system consists of two successive alpha-scintillation cells and photomultipliers, and counting electronics. Continuous helium gas flow purges ^<219>Rn and ^<220>Rn from MnO_2 fiber on which ^<227>Ac and ^<228>Ra are adsorbed and intuduce them into the alpha-scintillation cells. various experiments were carried out to find optional and prored that the system is useful for simoltaneous determinations of ^<227>Ac and ^<228>Ra.

锕-227是属于铀<235>衰变链的核素。它的半衰期（21.7年）与^ Pb的半衰期<210>（t &lt;1/2&gt;= 22.7年）相当。虽然^<210>-Pb被广泛用作大型、海岸和陆架沉积物的定年工具以及海洋环境中重金属的示踪剂，但<227>由于缺乏简便的测定方法，^-Pb在地球化学问题中的应用受到限制。本研究的目的是发展一种新的计数方法，它包括用α闪烁池探测短寿命氡（~ <219>3Rn和~ 4 <220>Rn）及其衰变产物，该系统由两个连续的α闪烁池、光电倍增管和计数电子学组成。连续氦气流将<219>吸附<220>有^ Ac和^ Ra的MnO_2纤维上的^ Rn和^ Rn<227><228>吹扫并导入α闪烁池。进行了各种实验以寻找可选方案，并证明该系统可用于同时测定^<227>Ac和^<228>Ra。

项目成果

野崎 義行: "現代海洋化学の展望" 月刊海洋. 号外8. 5-12 (1995)

野崎义幸：《现代海洋化学的展望》月刊特刊8. 5-12 (1995)。

酒井 均: "Biogeochemical Processes and Ocean Flux in the Western Pacific." Terra 学術図書出版, 672 (1995)

Hitoshi Sakai：“西太平洋的生物地球化学过程和海洋通量” Terra 学术出版，672 (1995)

野崎 義行: "Chemical and radiochemical investigation of sediment cores from the 9750 m bottom of the Bonin Trench." Mar.Technol. Soc. Jour.29. 32-41 (1995)

Yoshiyuki Nozaki：“Bonin 海沟底部沉积物的化学和放射化学研究”，Mar.Technol.29（1995 年）。

野崎 義行: "気候システムと気候変動" 太陽エネルギー. 21. 9-14 (1995)

Yoshiyuki Nozaki：“气候系统和气候变化”太阳能。21. 9-14 (1995)

野崎 義行: "海水中の希土類元素の地球化学" 月刊海洋. 号外8. 30-36 (1995)

野崎义之：“海水中稀土元素的地球化学”月刊特刊8. 30-36 (1995)。