...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review, C >New measurements of low-energy resonances in the Ne-22(p, gamma)Na-23 reaction
【24h】

New measurements of low-energy resonances in the Ne-22(p, gamma)Na-23 reaction

机译：NE-22（P，GAMMA）Na-23反应中的低能量共振的新测量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Ne-22(p, gamma)Na-23 reaction is one of the most uncertain reactions in the NeNa cycle and plays a crucial role in the creation of Na-23, the only stable Na isotope. Uncertainties in the low-energy rates of this and other reactions in the NeNa cycle lead to ambiguities in the nucleosynthesis predicted from models of thermally pulsing asymptotic giant branch (AGB) stars. This in turn complicates the interpretation of anomalous Na-O trends in globular cluster evolutionary scenarios. Previous studies of the Ne-22(p, gamma)Na-23 , Ne-22(He-3, d)Na-23, and C-12(C-12, p)Na-23 reactions disagree on the strengths, spins, and parities of low-energy resonances in Na-23 and the direct-capture Ne-22(p, gamma)Na-23 reaction rate contains large uncertainties as well. In this work we present new measurements of resonances at E-r(c.m.) = 417, 178, and 151 keV and of the direct-capture process in the Ne-22(p, gamma)Na-23 reaction. The resulting total Ne-22(p, gamma)Na-23 rate is approximately a factor of 20 higher than the rate listed in a recent compilation at temperatures relevant to hot-bottom burning in AGB stars. Although our rate is close to that derived from a recent Ne-22(p, gamma)Na-23 measurement by Cavanna et al. in 2015, we find that this large rate increase results in only a modest 18% increase in the Na-23 abundance predicted from a 5 M-circle dot thermally pulsing AGB star model from Ventura and D'Antona (2005). The estimated astrophysical impact of this rate increase is in marked contrast to the factor of similar to 3 increase in Na-23 abundance predicted by Cavanna et al. and is attributed to the interplay between the Ne-22(p, gamma)Na-23 and Ne-22(p, gamma)Na-23 reactions, both of which remain fairly uncertain at the relevant temperature range.
机译：Ne-22（p，γ）Na-23反应是NeNa循环中最不确定的反应之一，在Na-23（唯一稳定的Na同位素）的生成中起着关键作用。NeNa循环中这一反应和其他反应的低能率的不确定性导致了热脉冲渐近巨支（AGB）恒星模型预测的核合成的模糊性。这反过来又使球状星团演化情景中异常Na-O趋势的解释变得复杂。之前对Ne-22（p，伽马）Na-23、Ne-22（He-3，d）Na-23和C-12（C-12，p）Na-23反应的研究在Na-23中低能共振的强度、自旋和平价上存在分歧，直接捕获Ne-22（p，伽马）Na-23反应速率也包含很大的不确定性。在这项工作中，我们提出了在E-r（c.m.）=417178和151千电子伏时共振的新测量方法，以及Ne-22（p，γ）Na-23反应中直接俘获过程的新测量方法。由此产生的Ne-22（p，伽马）Na-23总速率比最近一次汇编中列出的AGB恒星热底燃烧相关温度下的速率大约高20倍。尽管我们的速率接近于Cavanna等人在2015年对Ne-22（p，γ）Na-23进行的最新测量得出的速率，但我们发现，这种速率的大幅增加只导致文图拉和D’Antona（2005）的5米圆点热脉冲AGB星模型预测的Na-23丰度略微增加18%。该速率增加的估计天体物理影响与Cavanna等人预测的Na-23丰度增加类似3的因素形成了显著对比，并归因于Ne-22（p，伽马）Na-23和Ne-22（p，伽马）Na-23反应之间的相互作用，两者在相关温度范围内仍然相当不确定。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号