Resonant scattering of 22 Na + p studied by the thick-target inverse-kinematic method
Resonant scattering of 22 Na + p studied by the thick-target inverse-kinematic method
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DOI：
10.1103/physrevc.88.035801
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发表时间：
2013-09
影响因子：
3.1
通讯作者：
S. Jin;Y. B. Wang;Jun Su;S. Yan;Y. J. Li;B. Guo;Z. Li;S. Zeng;G. Lian;X. Bai;Weiping Liu;H. Yamaguchi;S. Kubono;J. Hu;D. Kahl;H. Jung;J. Moon;C. S. Lee;T. Teranishi;Hong-Wei Wang;H. Ishiyama;N. Iwasa;T. Komatsubara;B. A. Brown
中科院分区：
文献类型：
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作者：
S. Jin;Y. B. Wang;Jun Su;S. Yan;Y. J. Li;B. Guo;Z. Li;S. Zeng;G. Lian;X. Bai;Weiping Liu;H. Yamaguchi;S. Kubono;J. Hu;D. Kahl;H. Jung;J. Moon;C. S. Lee;T. Teranishi;Hong-Wei Wang;H. Ishiyama;N. Iwasa;T. Komatsubara;B. A. Brown
背景：在极前低密度石墨颗粒中，发现了一个极大的Ne-22/Ne-20比值，甚至接近纯的Ne-22，这表明放射性的Na-22在颗粒中发生了凝聚。超新星和富霓新星是通过爆炸氢燃烧过程产生Na-22的主要事件。Na-22(p，Gamma)Mg-23反应是影响抛射中Na-22丰度的关键反应之一。目的：本工作旨在探索与天体物理Na-22(p，Gamma)Mg-23反应相关的Mg-23质子共振态。方法：通过H-1(Ne-22，Na-22)n反应产生低能的Na-22放射性离子束，用传统的厚靶逆运动学方法测量Na-22+p共振散射的激发函数。用R-矩阵分析从实验激发函数中推导出了MG-23的共振参数。结果：观察到了三种质子共振态。确定了自旋/奇偶数和质子的部分宽度。结论：新的自旋和宇称赋值允许我们进行壳层模型的计算。用于评价Na-22(p，伽马)镁-23天体物理反应率的镁-23共振态宽度。在Mg-23中分别建立了8.793 MeV和8.916 MeV的两个S波共振态，在大于2GK的温度下，总反应速率提高了约5%。
Background: In presolar low-density graphite grains, an extraordinarily large Ne-22/Ne-20 ratio or even nearly pure Ne-22 is found, pointing to the condensation of radioactive Na-22 in grains. Supernovae and neon-rich novae are the main events that produce Na-22 via the explosive hydrogen burning process. The Na-22(p,gamma)Mg-23 reaction is one of the key reactions that influences the Na-22 abundance in ejecta.Purpose: The present work aims to explore the proton resonant states in Mg-23 relevant to the astrophysical Na-22(p,gamma)Mg-23 reaction. The determined Mg-23 resonant parameters can be used to evaluate the Na-22(p,gamma)Mg-23 reaction rate.Method: A low-energy Na-22 radioactive ion beam is produced via the H-1(Ne-22, Na-22)n reaction, and used to measure the experimental excitation function of the Na-22 + p resonant scattering with a conventional thick-target inverse kinematic method. R-matrix analysis is applied to deduce the Mg-23 resonance parameters from the experimental excitation function.Results: Three proton resonance states in Mg-23 are observed. Spins/parities and the proton partial widths are determined. The deduced excitation energies agree with the compiled values.Conclusions: The new spin and parity assignments allow us to perform a shell-model calculation of the. widths of the Mg-23 resonant states for the evaluation of the Na-22(p,gamma) Mg-23 astrophysical reaction rate. The two s-wave resonant states established in this work at 8.793 and 8.916 MeV in Mg-23, respectively, increase the total reaction rate by about 5% at a temperature greater than 2 GK.