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.

远离稳定核的奇异结构为我们理解原子核提供了严格的检验，因而引起了人们极大的兴趣。本文提出了一种确定远离稳定核激发态自旋宇称的新方法。其实质是，我们观察到的β衰变各向异性的自旋极化放射性核与β延迟粒子的巧合。我们将把这种方法应用到11Li中，以研究N=8中子魔数在非常丰中子核中的消失。在2001年和2002年，我们完成了以下准备工作：（1）获得高极化的11Li束流，（2）建造专用束线，（3）建造β射线、β缓发中子和γ射线探测器系统，所有这些工作都在2003财年年底完成。原定于2003年6月的束流时间因加速器故障而推迟。试验定于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。

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)。

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（

T.Ishikawa 他: "Measurement of the ^<16>N(α, n) Reaction Cross Section"Nuclear Physics. A718. 484c-486c (2003)

T. Ishikawa 等人：“^ 16 N(α，n)反应截面的测量”核物理484c-486c。