Experimental cross sections of Ho 165 ( α , n ) Tm 168 and Er 166 ( α , n ) Yb 169 for optical potential studies relevant for the astrophysical γ process
Experimental cross sections of Ho 165 ( α , n ) Tm 168 and Er 166 ( α , n ) Yb 169 for optical potential studies relevant for the astrophysical γ process
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Ho 165 ( α , n ) Tm 168 和 Er 166 ( α , n ) Yb 169 的实验横截面，用于与天体物理 γ 过程相关的光学势研究
DOI：
10.1103/physrevc.89.065808
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发表时间：
2014
影响因子：
3.1
通讯作者：
M. Wiescher
中科院分区：
文献类型：
--
作者：
J. Glorius;K. Sonnabend;J. Görres;D. Robertson;M. Knörzer;A. Kontos;T. Rauscher;R. Reifarth;A. Sauerwein;E. Stech;W. Tan;T. Thomas;M. Wiescher
背景：光势是预测天体物理过程模拟所需的核反应速率的关键因素。对于涉及粒子的反应，相关的不确定性特别大。这包括过程中特别重要的反应。目的：反应的测量可以优化当前使用的核势。反应并探测质量区域中的光学模型，其中过程计算显示出尚未理解的核生成不足。方法：为了研究反应的能量相关横截面并接近反应阈值，使用圣母大学的 FN 串联范德格拉夫加速器用粒子照射自支撑金属箔。随后通过监测特定衰变通道来确定诱导活动。结果：具有广泛使用的全局势的豪瑟-费什巴赫预测很好地描述了横截面几乎完全对宽度敏感的能量处的数据。在较低能量下，反应阈值的差异似乎越来越大。结论：测试的全局电势适用于高于 14 MeV 的能量，而在接近反应阈值时似乎有必要进行修改。由于 和 中子宽度对预测显示出不可忽略的影响，因此需要补充数据来判断所发现的差异是否可以单独归因于宽度。
Background:Optical potentials are crucial ingredients for the prediction of nuclear reaction rates needed in simulations of the astrophysicalprocess. Associated uncertainties are particularly large for reactions involvingparticles. This includesreactions which are of special importance in theprocess.Purpose:The measurement ofreactions allows for an optimization of currently used-nucleus potentials. The reactionsandprobe the optical model in a mass region whereprocess calculations exhibit an underproduction ofnuclei which is not yet understood.Method:To investigate the energy-dependent cross sections of the reactionsandclose to the reaction threshold, self-supporting metallic foils were irradiated withparticles using the FN tandem Van de Graaff accelerator at the University of Notre Dame. The induced activity was determined afterwards by monitoring the specific-decay channels.Results:Hauser-Feshbach predictions with a widely used globalpotential describe the data well at energies where the cross sections are almost exclusively sensitive to thewidths. Increasing discrepancies appear towards the reaction threshold at lower energy.Conclusions:The tested globalpotential is suitable at energies above 14 MeV, while a modification seems necessary close to the reaction threshold. Since theand neutron widths show non-negligible impact on the predictions, complementary data are required to judge whether or not the discrepancies found can be solely assigned to thewidth.