Spectroscopic Study of Neutron-Rich Nuclei with Spin-Polarized Radioactive Nuclear Beams

自旋极化放射性核束对富中子核的光谱研究

• 批准号: 14340073
• 负责人: SHIMODA Tadashi
• 金额: $ 10.75万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340073/
• 关键词: unstable nucleus; polarized 11Li beam; beta-delayed neutron decay; excited states; 11Be; spin-parity assignment; スピン偏極; 傾斜薄膜法; 偏極電子移行反応; レーザー光ポンピング; 11Be

The exotic structure of nuclei far from the stability are attracting much interest because they provide stringent tests for our understanding of nuclei. We propose a new method to determine the spin-parities of excited states of nuclei far from the stability. The essential point is that we observe the beta-decay anisotropy from a spin polarized radioactive nucleus in coincidence with beta-delayed particles. We will apply this method to 11Li in order to investigate the disappearance of the N=8 neutron magic number in very neutron rich nuclei.The research proposal has been approved with high priority at ISAC facility of TRIUMF in Canada, which is a state-of-the-art radioactive nuclear beam facility. In 2001 and 2002, we achieved the following preparatory works :(1)Achieving highly polarized 11Li beam,(2)Constructing a dedicated beam-line(3)Constructing detector systems for beta-rays, beta-delayed neutrons, and gamma-rays.All have been done by the end of FY2003. The scheduled beam time in June 2003 was postponed due to accelerator trouble. The experiment is scheduled in July 2004.

远离稳定的原子核的奇异结构引起了人们的极大兴趣，因为它们为我们对原子核的理解提供了严格的测试。我们提出了一种新方法来确定远离稳定的核激发态的自旋宇称。要点是我们观察到自旋极化放射性核的 β 衰变各向异性与 β 延迟粒子一致。我们将把这种方法应用到 11Li 上，以研究非常富中子核中 N=8 中子幻数的消失。该研究提案已在加拿大 TRIUMF 的 ISAC 设施获得高度优先批准，这是一个国家级的研究机构。 -最先进的放射性核束设施。 2001年和2002年，我们完成了以下准备工作：（1）实现高偏振11Li束流；（2）构建专用束线；（3）构建β射线、β延迟中子和γ射线探测器系统.所有工作均已于 2003 财年年底完成。由于加速器故障，原定于 2003 年 6 月发射的光束时间被推迟。该实验计划于 2004 年 7 月进行。

项目成果

T.Shimoda 他: "A Spin Polarizer for Radioactive Nuclear Beams by Taking Advantage of Polarized Electron Transfer Reactions"Nuclear Physics.. A701. 583c-587c (2002)

T. Shimoda 等人：“利用极化电子转移反应的放射性核束的自旋偏振器”核物理.. A701 (2002)。

A.Hatakeyama et al.: "Optical Pumping at the ISAC Polarizer"Proc. of the Ninth Int.Workshop on Polarized Sources and Targets, nashville, USA, Sept.30 -Oct.4, 2001 (World Scientific). 339-343 (2002)

A.Hatakeyama 等人：“ISAC 偏振器的光泵浦”Proc。

H.Miyatake et al.: "Spin-parity Assignments in ^<15>C^* by a New Method : Beta-Delayed spectroscopy for a Spin-polarized Nucleus"Physical Review C. 67. 014306-1-014306-9 (2003)

H.Miyatake等人：“通过新方法在^ 15 C ^ *中进行自旋宇称分配：自旋极化核的β延迟光谱”物理评论C. 67。014306-1-014306-9（

A.Hatakeyama 他: "Optical pumping at the ISAC polarizer"PST2001 Proceedings (World Scientific). 339-343 (2002)

A. Hatakeyama 等人：“ISAC 偏振器的光泵浦”PST2001 论文集（世界科学）339-343 (2002)。

Y.Hirayama et al.: "Structure of ^<11>Be Studied in β-delayed Decays from Polarized ^<11>Li"Physics Letters B. (submitted). (2004)

Y. Hirayama 等人：“在极化 ^<11>Li 的 β 延迟衰变中研究 ^<11> 的结构”《物理学快报 B》（2004 年提交）。