Spin and parity of the excited states of a neutron-halo nucleus ィイD111ィエD1Be

中子晕核激发态的自旋和宇称

• 批准号: 09640347
• 负责人: NAKAMURA Masanobu
• 金额: $ 1.92万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640347/
• 关键词: UNSTABLE NUCLEI; NEUTRON HALO; SPIN; POLARIZATION; 中性子ハロ-; パリティ; 偏極ビーム

The developments of radioactive beam, produced through the projectile-fragmentation process are opening a new field of nuclear physics : the structure of unstable nuclei. The nucleus ィイD111ィエD1Be shows a remarkably large interaction radius and this is the best known case of a one-neutron halo nuclei. But, there is a little experimental information, and the effort to acquire knowledge in the various parity of the final state by using the ィイD110ィエD1Be (d, p) ィイD111ィエD1Be reaction. As for the ィイD110ィエD1Be target, the BeO on platinum foil was used. The energy of the excited state arid the life of the unstable nucleus which was produced by he (d, p) reaction were examined from the measurement of the gamma ray and the beta ray, and the formation of 11Be was confirmed. The impurities of the oxide that the surface of platinum foil were examined by using the backward proton scattering, and it was found out that there were many C and O in comparison with Be about two orders. Therefore, it found out that it was difficult to measure the analyzing power for the proton of the (d, p) reaction by using this target.The polarized deuteron beam was obtained from the Kyoto University Tandem Accelerator. The ion source was the atomic-beam type and the improvement of time this source was done on a parallel with the development of the ィイD110ィエD1Be target. The polarized proton beam of several 10 nA could be formed stably by remodeling the cooling system of the dissociator nozzle, the magnet of the weak-field RF transition, the pumping system of the ECR ionizer and the charge exchange part and so on.The polarized deuteron measurement becomes possible by the installation of the device which controls the spin such as a Wien filter. The development of the thin target of ィイD110ィエD1Be with a very thin support is the future subject.

通过射弹碎裂过程产生的放射性束流的发展正在开辟核物理的一个新领域：不稳定核的结构。原子核D111 D1 Be显示出非常大的相互作用半径，这是单中子晕核中最著名的例子。但是，有一点实验信息，并努力获得知识，在各种宇称的最后状态，通过使用的<$N D110 <$N D1 Be（d，p）<$N D111 <$N D1 Be反应。至于铍D110铍D1 Be靶，使用铂箔上的BeO。通过γ射线和β射线的测量，研究了He（d，p）反应产生的不稳定核的激发态能量和寿命，证实了11Be的形成。用后向质子散射法对铂箔表面氧化物中的杂质进行了检测，发现其中含有较多的C和O，与Be相比约为两个数量级。利用京都大学串列加速器获得的极化氘核束流，对（d，p）反应质子的解析功率进行了测量。离子源是原子束型的，这种源的时间改进是与D110靶的开发并行进行的。通过对离解器喷嘴冷却系统、弱场射频跃迁磁铁、ECR电离器抽运系统和电荷交换部分等的改造，可以稳定地形成几十nA的极化质子束流，通过安装维恩滤波器等控制自旋的装置，使极化氘核的测量成为可能。具有极薄支撑的超导体D110超导体D1 Be薄靶的开发是未来的课题。

项目成果

M.Nakamura: "Polovized Negafive Jon Source at the Kyoto University Tandem Accelerator" AIP Conference Proceedings. 421. 509-510 (1998)

M.Nakamura：“京都大学串联加速器的极化负面 Jon Source”AIP 会议记录。