INTERACTION OF BETA-RADIOACTIVE ATOMS IN LIQUID HELIUM

液氦中 β 放射性原子的相互作用

• 批准号: 04640299
• 负责人: TAKAHASHI Noriaki
• 金额: $ 1.47万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640299/
• 关键词: Radioactive nuclear beam; Superfuluid helium; Snowball; Beta detection method; Alpha detection method; Nuclear polarization; Cluster; ベータ線

Radioactive he, Li andB isotopes produced by heavy-ion reactions were ofrmed into fast radioactive nuclear beans and were introduced into liquid helium. Most of the introduced ions are nutralized but still some remain as singly-charged ions. Their spatial distribution changes with time. Solid-state alpha-and teta-ray detectors and pasition sensitive beta-ray detectors enabled us to indentify and trace the spatial distributions. With use of detectors interactions of impurity ions and Bose condensation waer studied. Ion planted solid state detectors working at liquid He temperature were mounted in a cryostat and the study of interaction of impurity ions with superfluid helium became passible only after the ontroduction of the two detection methods stated above. The detection efficiency largely exceeded that of the conventional electric aharge measurements. A cryostat incorporating of 1.2 K.Heavy-ion beams obtained from the ring cyclotron of RCNP, Osaka Unversity were led to the secondary beam (EN) course and radioactive nuclear beans were formed. The behavior of ions and neutralized atoms was studied with use of Li and B.Nuclear spin polarization was proved for the first time to ve maintained in a micro-cluster of He atoms in superfluid helium. A huge first stop has been trodden for the study of nuclear, low-temperature and condensed-matter (say cluster) Physices.

重离子反应产生的放射性氦、锂和硼同位素被制成快放射性核豆，并被引入液氦中。大多数引入的离子是营养化的，但仍有一些仍然是单电荷离子。它们的空间分布随时间变化。固态阿尔法和四射线探测器以及位置灵敏的贝塔射线探测器使我们能够识别和跟踪空间分布。用探测器研究了杂质离子与玻色凝聚的相互作用。将工作在液氦温度下的离子注入固体探测器安装在低温恒温器中，只有在引入上述两种检测方法后，才有可能研究杂质离子与超流氦的相互作用。该方法的探测效率大大超过了传统的电离测量方法。从大阪大学RCNP环回旋加速器获得的1.2K重离子束被引入二次束(EN)过程中，形成了放射性核豆。用Li和B研究了离子和中和原子的行为，首次证明了在超流氦中，核自旋极化一直保持在He原子的微团簇中。原子核、低温和凝聚态(比方说星系团)物理的研究已经踏上了巨大的第一站。

项目成果

N.Takahashi et al.: "Freezing-Out of Nuclear Polarization in Core Ions of Micro-Clusters “Snowballs" in Superfluid Helium" Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei. (1994)

N. Takahashi 等人：“超流氦中微团簇“雪球”核心离子的核极化冻结”强子和原子核中的自旋同位旋响应和弱过程（1994）。

N.Takahashi et al.: "Ffeezing-Out of Nuclear Polarization in Cre Ions of Micro-Clusters "Snowballs" in Superfluid Helium" Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei. (1994)

N.Takahashi 等人：“超流氦中微团簇“雪球”Cre 离子中核极化的 Ffeezing-Out”强子和原子核中的自旋同位旋响应和弱过程。

K.Asahi: "Spin-Oriented Projectile Fragments:The First Application To g-Factor Measurements" Hyperfine Interactions. 75. 101-108 (1992)

K.Asahi：“旋转定向弹丸碎片：g 因子测量的首次应用”超精细交互。

Noriaki Takahashi: "Snowballs:Micro-Clusters Versatile in Nuclear and Condensed-Matter Physics" Nuclear Structure and Interdisciplinary Topics. 238-245 (1992)

高桥纪明：“雪球：核物理和凝聚态物理中多功能的微团簇”核结构和跨学科主题。

H.Okuno et al.: "Plarization in Projectile Fragmentation and g-Factor Measurements for Neutron-Rich Nuclei" Hyperfine Interactions. 78. 97-103 (1993)

H.Okuno 等人：“弹丸碎裂中的极化和富中子核的 g 因子测量”超精细相互作用。