Study of Nuclear Spin Excitations through All Polarization Transfer Measurements

通过全偏振转移测量研究核自旋激发

• 批准号: 07454051
• 负责人: YOSOI Masaru
• 金额: $ 5.12万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454051/
• 关键词: polarization transfer coefficients; nuclear spin excitation; focal plane polarimeter; spectrometer Grand Raiden; 0ﾟ inelastic scattering; second-level trigger; fast data acquisition system; reflective memory; 陽子全偏極移行測定; 高分解能磁気分析器Grand Raiden; 高速

A main purpose of this research is to investigate spin excitations to unnatural parity states in nuclei by measuring all polarization transfer coefficients (D_<ij>'s) of proton scattering using a high resolution spectrograph and a focal plane polarimeter (FPP). The construction of the whole FPP system has been finished after newly introducing two MWPC's for measuring incident direction to its analyzer target of double scattering, which has been made by this Grant-in-Aid for Scientific Research. Moreover we have developed a high-speed dataacquisition system(-1Mbyte/sec)by excluding CAMAC actions from data flow.We have succeeded for the first time to measure D_<ij>'s in proton inelastic scattering off ^<12>C and ^<28>Si at zero degrees by fully utilizing above system. The results have shown that even the isoscalar spin-dependent term V_o, which is the smallest part of effective nucleon-nucleon (NN) interactions, can be 'determined with less ambiguities through the transitious to isoscalar 1^+ states. In addition, we have demonstrated that cross sections can be clearly disentangled with respect to the spin-flip and non spin-flip parts by a combination of all D_<ij'>. A selectivity of the isospin of the spin-flip transitions has also been found. As another theme, spin rotation parameters of proton elastic scattering have been measured by using this FPP system and medium modifications of NN interaction has been studied. Sonic new relevant experiments which investigate resonance modes of highly excited states and distributions of neutron densities are now under progress.

本研究的一个主要目的是利用高分辨摄谱仪和焦平面偏振仪（FPP）测量质子散射的全极化转移系数（D_s），研究核中非自然宇称态的自旋激发<ij>。本项目引进了两台用于测量双散射分析靶入射方向的多波长光电倍增管，完成了整个FPP系统的搭建。此外，我们还研制了一个高速数据采集系统（~ 1 Mbyte/sec），将CAMAC作用排除在数据流之外，并利用该系统首次成功地测量了零度下<ij>质子在^ C和^ Si上的非弹性散射D_s<12><28>。结果表明，即使是核子-核子（NN）有效相互作用中最小的同位旋自旋相关项V_o，也可以通过跃迁到同位旋1^+态来确定。此外，我们还证明了通过所有D_&lt;ij '&gt;的组合，可以清楚地对自旋翻转和非自旋翻转部分的截面进行解纠缠。另外，利用该FPP系统测量了质子弹性散射的自旋转动参数，并研究了NN相互作用的介质修正。研究高激发态共振模式和中子密度分布的新的相关实验正在进行中。

项目成果

A.Tamii et al.: "Spin Excitations by ^<12>C (p, p') Reactions at rheta=0 Degrees" Proc.Int.Sympo.on "New Facet of Spin-Giant Resonances in Nuclei". 424-433 (1998)

A.Tamii 等人：“rheta=0 度时^ 12 C (p, p) 反应的自旋激发”Proc.Int.Sympo.on“原子核中自旋巨共振的新方面”。

H.Sakaguchi 他: "Elastic Scattering of Polarized Protons from ^<58>Ni at E_p = 192,295, and '400 MeV" Physical Review C. 57. 1749-1755 (1998)

H. Sakaguchi 等人：“E_p = 192,295 和 400 MeV 时来自 ^<58>Ni 的极化质子的弹性散射”物理评论 C. 57. 1749-1755 (1998)

H.Sakaguchi et al.: "Elastic Scattering of Polarized Protons from ^<58>Ni at Ep=192,295, and 400 MeV" Physical Review. C57. 1749-1755 (1998)

H.Sakaguchi 等人：“Ep=192,295 和 400 MeV 时来自 58 Ni 的极化质子的弹性散射”物理评论。

M. yosoi 他: "Fcal plane polarimeter for the GRAND RAIDEN at RCNP" AIP Conference Proceedings. 343. 157-161 (1995)

M. yosoi 等人：“RCNP GRAND RAIDEN 的 Fcal 平面旋光计”AIP 会议论文集 343. 157-161 (1995)。

Y. Fujita 他: "Isospin decomposition of the Gamow-Teller strength in ^<58>Cu" Physics Letters B. 365. 29-34 (1996)

Y. Fujita 等人：“^<58>Cu 中 Gamow-Teller 强度的同位旋分解”Physics Letters B. 365. 29-34 (1996)