Transport and Extraction of Radioactive Ions in Superfluid Helium

超流氦中放射性离子的传输和提取

• 批准号: 14540283
• 负责人: TAKAHASHI Noriaki
• 金额: $ 2.18万
• 依托单位: Osaka Gakuin University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540283/
• 关键词: Superfluid Helium; Impurity Ions; Radiation Detection Method; Snowball; Nuclear Polarisation; Extraction of Positive Ions; Transport Phenomena; Potential Barrier

Described here are experiments on the transport under electric field and the extraction of impurities from the surface of superfluid helium. As impurities we introduced radioactive heavy ions into helium. We established an experimental method of production, transport and extraction of ions in superfluid helium by using radiation detection method. With this method we tackled with determination of extraction probability, its dependence on temperature and barrier height at the interface of liquid-vapour phases.The improvements realised were ; 1.extraction potential barrier for the positive ions has been determined for the first time and this is almost equivalent for the extraction of electrons. 2.The snowball production rate at the 215Po source has been improved by applying higher electric field on the surface of the source. 3.The extraction has become more effective by using pulsed second sound for raising locally and instantaneously the surface temperature. We attained the precise determination of probability, its temperature dependence on barrier height. Nuclear spectroscopy experiments with radioactive nuclear beams have been developed further in parallel with these.Rich variety of heavy-ion reaction products will be stopped in superfluid helium and emerge as ultra-cold (zero- energy) radioactive beams. It is expected that this novel method is applicable in the new projects planned in the world. The GSI Darmstadt is counted as one of such institutions.

这里描述的是电场下的输运和从超流氦表面提取杂质的实验。作为杂质，我们将放射性重离子引入氦气中。我们建立了利用辐射检测方法在超流氦中产生、传输和提取离子的实验方法。通过这种方法，我们解决了提取概率的确定问题，及其对液-汽相界面温度和势垒高度的依赖性。所实现的改进是： 1.首次确定了正离子的引出势垒，这几乎相当于电子的引出势垒。 2.通过在源表面施加更高的电场，提高了215Po源的雪球生产率。 3.利用脉冲第二声局部瞬时提高表面温度，使萃取变得更加有效。我们实现了概率及其温度对势垒高度的依赖性的精确确定。与这些同时进行的放射性核束核光谱实验也得到了进一步发展。丰富多样的重离子反应产物将在超流氦中停止并以超冷（零能量）放射性束的形式出现。预计这种新颖的方法适用于世界各地规划的新项目。 GSI 达姆施塔特被视为此类机构之一。

项目成果

Measurement of the 16N(α,n) Reaction Cross Section

16N(α,n) 反应截面的测量

• 发表时间: 2003
• 作者: T.Ishikawa et al.

Direct Measurements of (α,n) and (p,n) Reaction Cross Sections Using Light Neutron-Rich Radioactive Nuclear Beams

使用轻中子富放射性核束直接测量 (α,n) 和 (p,n) 反应截面

• 发表时间: 2003
• 作者: H.Ishiyama; T.Hashimoto; T.Kawamura; T.Ishikawa; H.Miyatake; M.H.Tanaka; Y.Fuchi; N.Yoshikawa; S.C.Jeong; Y.Watanabe; H.Kawakami; I.Katayama; T.Nomura; S.Mitsuoka; K.Nishio; M.Matsuda; S.Ichikawa; H.Ikezoe; T.Furukawa; H.Yano; H.Izumi; Y.Mizoi; M.Terasawa
• 通讯作者: M.Terasawa

Spin Polarization of Low-Energy Radioactive Nuclear Beams by Tilted-Foil Technique

利用倾斜箔技术实现低能放射性核束的自旋极化

• 发表时间: 2002
• 作者: S.Shimizu et al.

Extraction of radioactive positive ions across the surface of superfluid helium -A new method to Produce cold radioactive nuclear beams-

超流氦表面放射性正离子的提取-产生冷放射性核束的新方法-

• 发表时间: 2003
• 作者: W.X.Huang; P.Dendooven; K.Gloos; K.Arutyunov; N.Takahashi; J.P.Pekola; J.Aysto
• 通讯作者: J.Aysto

A Spin Polarizer for Radioactive Nuclear Beams by Taking Advantage of Polarized Electron Transfer Reactions

利用极化电子转移反应的放射性核束自旋偏振器

• 发表时间: 2002
• 作者: T.Shimoda; S.Shimizu; E.Doumoto; M.Yagi; M.Asai; M.Nakamura; Y.Hirayama; K.Horie; T.Shigematsu; H.Izumi; N.Takahashi
• 通讯作者: N.Takahashi