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

基本信息

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

项目摘要

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

该实验是在Tohoku University的Cyclotron和Releisotope Center上进行的，来自K = 110mev AVF-Cyclotron的70 mev质子束和新的Beam Swinger Swinger System^<6）>。已经描述了实验设置的细节参考文献6。中子能通过飞行时间（TOF）测量，其中中子是通过检测器阵列检测到的中子，该检测器阵列由16个条件的磁盘型检测器的16条处理距离位于距离目标44.3 m。探测器在总敏感体积中填充25.1升有机液体闪烁体BC501A。检测器的绝对效率是从误差小于6％的误差（p，n） ^7BE激活分析中获得的。估计（P，N）横截面的绝对大小中的误差估计小于12％。该靶标是 ^6li同位素的金属箔，其富集大于95％。 ^6Li（p，n） ^6BE反应的实验研究已在E_P = 50 ^-80 MEV区域进行。测量了中性的差分横截面……更多导致残留核五个状态的更多ONS。结果已与基于DW理论的大空间壳模型预测进行了比较。 E_X = 3mev处的新观察到的低洼状态已暂定为2^+，t = 1一个。在E_X = 15和25MEV处观察到两个宽大的凸起，为Δl= 1的1^ - 和2^ - 成分。在E_P = 70 MEV上进行了^<12> C（P，N）^<12> N反应的经验研究，比那些远面报道的分辨率更好。将结果与基于大空间壳模型和DW计算的预测进行了比较，在该计算中，应用了Franey和Love 100MEV有效相互作用。观察到的七个过渡的自旋 - 差异分配与先前的报告一致。 ^<42> Ca（p，n） ^<42> sc反应在E_P = 50、70和80 MEV时通过高分辨率TOF技术观察到。壳模型计算和DWBA理论的分析分别为 ^<42,44> sc和 ^<48> sc核提供了一组自旋 - 平性分配。 GT矩阵元件B（GT）是从LA和GT横截面建立的。等级有效相互作用强度| J_<στ>/J_τ|的能量依赖性|在50至80 MeV之间的中等质量核上（P，N）反应获得了（P，N）反应。较少的