Study of Spin-isospin Excitation by the (p,n) Reaction in the Energy Rang in E_p=10^* 100MeV

E_p=10^* 100MeV能量范围内(p,n)反应自旋-同位旋激发的研究

• 批准号: 13640257
• 负责人: ORIHARA Hikonojo
• 金额: $ 2.11万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640257/
• 关键词: (p,n) Reaction; Neutron Time-of-Flight; ^6Li(p,n)^6Be Reaction; Gamow-Teller Transition; Fermi Transition; Effective N-N Interaction; ^<42>Ca(p,n)^<42>ScReaction; V_τ; V_<στ> Ratio; 6^Li(p,n)^6Be反応

The experiment was performed at the Cyclotron and Radioisotope Center, Tohoku University, with a 70-MeV proton beam from the K=110MeV AVF-cyclotron and the new beam swinger system^<6)>. The details of the experimental setup have been described Ref.6. Neutron energies were measured by the time-of-flight technique (TOF), where neutrons were detected by a detector array consisting of 16peaces of the disk type detector located at 44.3 m from the target. The detectors were filled with 25.1-liter organic liquid scintillator BC501A in the total sensitive volume. The absolute efficiencies of the detectors were obtained from the ^7Li(p,n) ^7Be activation analyses with an error less than ± 6%. Errors in the absolute magnitude of (p,n) cross sections were estimated to be less than 12%. The target was a metallic foil of ^6Li isotopes with enrichments better than 95%.The experimental study for the ^6Li(p,n)^6Be reaction has carried out at E_p=50^- 80 MeV region. Differential cross sections of neutr … More ons leading to the five states in the residual nucleus were measured. Results have been compared with the large-space shell-model prediction based on DW theory. The newly observed low-lying state at E_x= 3MeV has been tentatively assigned to be 2^+, T=1 one. Two broad bump observed at E_x= 15 and 25MeV were discussed as 1^- and 2^- components of the ΔL=1 giant resonance.Experimental study of the ^<12>C(p,n)^<12>N reaction have been carried out at E_p= 70 MeV with better resolution than those so far reported. Results were compared successfully with the predictions based on large-space shell-model and DW calculations where Franey and Love 100MeV effective interactions were applied. Spin-parity assignments for observed seven transition were consistent with previous report.The ^<42>Ca(p,n)^<42>Sc reaction at E_p = 50, 70 and 80 MeV were observed by the high resolution TOF technique. The shell model calculation and analyses with DWBA theory have provided a set of spin-parity assignment over 7, 8 and 10 levels for ^<42,44>Sc, and ^<48>Sc nuclei, respectively. The GT matrix elements B(GT) were obtainded from the LAS and the GT cross sections. The energy dependence of the ratio of isovector effective interaction strengths |J_<στ>/J_τ| was obtained for the (p,n) reaction on a medium mass nucleus in an energy range between 50 and 80 MeV. Less

该实验在东北大学回旋加速器和放射性同位素中心进行，使用来自 K=110MeV AVF 回旋加速器的 70-MeV 质子束和新的光束摆动系统^<6)>。实验设置的细节已在参考文献 6 中进行了描述。中子能量通过飞行时间技术（TOF）测量，其中中子由距离目标44.3 m处的16个盘式探测器组成的探测器阵列探测。探测器的总敏感体积中填充有25.1升有机液体闪烁体BC501A。探测器的绝对效率通过^7Li(p,n) ^7Be 激活分析获得，误差小于±6%。 (p,n) 横截面的绝对大小误差估计小于 12%。目标是富集度大于95%的^6Li同位素金属箔。^6Li(p,n)^6Be反应的实验研究在E_p=50^- 80 MeV区域进行。测量了导致残余核中五种状态的中性子的微分横截面。结果与基于DW理论的大空间壳模型预测进行了比较。新观测到的 E_x= 3MeV 处的低洼态已暂定为 2^+, T=1 1。在E_x= 15和25MeV处观察到的两个宽凸块被讨论为ΔL=1巨共振的1^-和2^-分量。^<12>C(p,n)^<12>N反应的实验研究已经在E_p=70MeV处进行，其分辨率比迄今为止报道的更好。结果成功地与基于大空间壳模型和 DW 计算的预测进行了比较，其中应用了 Franey 和 Love 100MeV 有效相互作用。观察到的七个跃迁的自旋宇称分配与之前的报告一致。通过高分辨率TOF技术观察了E_p = 50、70和80 MeV时的^<42>Ca(p,n)^<42>Sc反应。壳模型计算和DWBA理论分析分别为^<42,44>Sc和^<48>Sc核提供了一组超过7、8和10级的自旋宇称分配。 GT 矩阵元素 B(GT) 是从 LAS 和 GT 横截面获得的。等向量有效相互作用强度之比的能量依赖性|J_<στ>/J_τ|是在能量范围为 50 至 80 MeV 的中等质量核上进行 (p,n) 反应而获得的。较少的

项目成果

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A.Terakawa、H.Suzuki、K.Kumagai 等人：“CYRI​​C 的新型快中子飞行时间设施”核仪器和方法。

H.Orihara, A.Terakawa, et al.: "Gamow-Teller matrix-elements in light nuclei and (p,n) cross-sections at E_p=35MeV"Physics Letters. B539. 40-44 (2002)

H.Orihara、A.Terakawa 等人：“轻核中的 Gamow-Teller 矩阵元素和 E_p=35MeV 处的 (p,n) 截面”《物理快报》。

A.Terakawa, H.Orihara, M.Oura, et al.: "Proton single-particle strength in ^<19>F measured via (d,n) reaction"Physical Review C. 66. 0064313 (2002)

A.Terakawa、H.Orihara、M.Oura等人：“通过(d，n)反应测量^ 19 F中的质子单粒子强度”Physical Review C.66.0064313(2002)

A.Terakawa, H.Orihara, M.Oura, M.Hosaka, T.Tohei, T.Nakagawa, J.Takamatsu, A.Narita, K.Hosomi, K,Ishii, G.C.Jon, K.Miura, and H.Ohnuma: Physical Review. C66. 0064313 (2002)

A.Terakawa、H.Orihara、M.Oura、M.Hosaka、T.Tohei、T.Nakakawa、J.Takamatsu、A.Narita、K.Hosomi、K、Ishii、G.C.Jon、K.Miura 和 H.

H.Orihara, A.Terakawa, et al.: "Gamow-Teller matrix-elements in light nuclei and (p, n) cross-sections at E_p= 35 MeV"Physics Letters. B539. 40-44 (2002)

H.Orihara、A.Terakawa 等人：“轻核中的 Gamow-Teller 矩阵元素和 E_p= 35 MeV 处的 (p, n) 截面”《物理快报》。