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= 110 MeV AVF回旋加速器和新光束摆动系统的70 MeV质子束^<6）>。实验装置的细节已在参考文献6中描述。中子能量的测量采用飞行时间技术（TOF），其中中子由位于距靶44.3 m处的16个盘型探测器组成的探测器阵列探测。探测器在总灵敏体积中填充有25.1升有机液体闪烁体BC 501 A。探测器的绝对效率由^7Li（p，n）^7Be活化分析得到，误差小于± 6%。（p，n）截面的绝对大小的误差估计小于12%。靶为富集度优于95%的^6Li同位素金属箔，在E_p=50^- 80 MeV区域进行了^6Li（p，n）^6Be反应的实验研究。中性粒子微分截面 ...更多信息 测量了剩余核中导致五个态的离子。并与基于DW理论的大空间壳模型预测结果进行了比较。新观察到的E_x= 3 MeV的低位态已被初步指定为2^+，T=1。本文讨论了在E_x= 15和25 MeV处观察到的两个宽凸点作为ΔL=1巨共振的1^-和2^-分量，并在E_p= 70 MeV处对^<12>C（p，n）^<12>N反应进行了实验研究，获得了比目前报道的更好的分辨率。结果进行了比较成功的预测大空间壳模型和DW计算的基础上，其中应用的Franey和Love 100 MeV的有效相互作用。用<42><42>高分辨飞行时间技术观察到了E_p = 50、70和80 MeV的^ Ca（p，n）^ Sc反应。壳模型计算和DWBA理论分析分别给出了^&lt;42，44&gt;Sc和^ Sc核的7、8和10能级自旋宇称分配<48>。从LAS和GT截面得到GT矩阵元B（GT）。等矢量有效相互作用强度比的能量依赖性|J_&lt;στ&gt;/J_τ|在50 ~ 80 MeV能量范围内，对中等质量核的（p，n）反应，得到了一个新的计算公式。少

项目成果

A.Terakawa, H.Suzuki, K.Kumagai, et al.: "New fast-neutron time of flight facilities at CYRIC"Nuclear Instruments and Methods. A491. 419-425 (2002)

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》。