High-Energy Heavy-Ion Reactions and Polarization in Matter

高能重离子反应和物质极化

• 批准号: 05044056
• 负责人: TAKAHASHI Noriaki
• 金额: $ 4.48万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05044056/
• 关键词: Radioactive Beam; Superfliud Helium; Snowball; Beta Detection Method; Alph Dectection Method; Nuclear Polarization

Nuclei produced in high-energy heavy-ion reactions are expected to sustaning polarization. The first stage of this research is to find radioactive nuclei sustaining large polarization. Cyclotrons of Osaka University and Riken, Tandem Accelerators of Rehovot and Legnaro were utilized to investigate the possibility. The SIS-FRS system at GSI was also effective to apply for such purposes.Possibilities of obtaining fast ions sustainig unclear polarization were tested experimentally at above laboratories ; the heavy polarized ions such as ^<93>Tc were obtained from the Legnaro tandem accelerator and the polarization and its preservation in a solid material were experimentally studied.The implantation into liquid helium was successfully carried out and the behavior of ions and nuclear polarization was further studied. In addition to the preservation of nuclear polarization in snowballs the folllowing facts are being studied. The stopping power of fast ions in liquid helium is double valued, one component as in normal matter and fluid, the other manifested in superfluid helium sustaining a range much longer then the former. This may be due to the collective flow in HeII.The measurements were carried out with radioactive beam and beta and alpha detection methods.The nuclear polarizaion may be destroyed when ions move in a strong electric field therefore evading the encapsulation in snowballs.The phenomenon will be further investigated.

在高能重离子反应中产生的原子核被认为具有持续极化的性质。这项研究的第一阶段是寻找维持大极化的放射性核。利用大坂大学和理研的回旋加速器，Rehoclave和Legnaro的串列加速器来研究这种可能性。GSI的SIS-FRS系统在这方面也取得了很好的应用效果。在上述实验室中，实验验证了获得极化不明显的快离子的可能性;<93>在Legnaro串列加速器上获得了重极化离子（如~（4 Tc）），实验研究了其在固体材料中的极化及其保持;成功地进行了液氦注入，并对离子的行为进行了研究并进一步研究了核极化。除了在雪球中保存核极化外，还在研究以下事实。快离子在液氦中的阻止本领是双值的，一个是正常物质和流体中的阻止本领，另一个是超流氦中的阻止本领，其作用范围远大于前者。这可能是由于HeII中的集体流.用放射性束和β、α探测方法进行了测量.当离子在强电场中运动时，核极化可能被破坏，从而避开了雪球的包裹.这一现象有待进一步研究.

项目成果

H.Okuno, K.Asahi, ...T.Shimoda, H.Miyatake, N.Takahashi, W.-D.Schmidt-Ott, M.Ishihara: "Systematic Behavior of Ejectile Spin Polarization in the Projectile Fragmentation Reaction" Physics Letters. B335. 29-34 (1994)

H.Okuno、K.Asahi、...T.Shimoda、H.Miyatake、N.Takahashi、W.-D.Schmidt-Ott、M.Ishihara：“射弹碎片反应中弹射自旋极化的系统行为”物理

T.Shimoda et al.: "Huge Spin-Polarization Observed in (^<14>N,^<12>B) Reactions on Au,Cu and Be at 40 MeV/u" Spin-Isospin Responses and Weak Processes in Hadrons and Nuclei. (1994)

T.Shimoda 等人：“在 40 MeV/u 下 Au、Cu 和 Be 的 (^<14>N,^<12>B) 反应中观察到巨大的自旋极化”强子和强子中的自旋同位旋响应和弱过程

N.Takahashi et al.: "Freezing-Out of Nuclear Polarization in Core Ions of Micro-Clusters “Snowballs" in Superfluid Helium" Nuclear Shapes and Nuclear Structure at Low Exitation Energy. (1994)

N. Takahashi 等人：“超流氦中微团簇“雪球”核心离子的核极化冻结”，低射出能量下的核形状和核结构（1994 年）。

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）。

Noriaki Takahashi: "Heavy-Ion Polarization at RCNP -Retrospect and Development into a New Phase-" Nuclear Physics. A577. 99c-102c (1994)

高桥纪明：“RCNP 的重离子极化 - 回顾和发展进入新阶段 -”核物理。