Thermonuclear 19F(p,alpha0)16O reaction rate
Thermonuclear 19F(p,alpha0)16O reaction rate
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热核 19F(p,alpha0)16O 反应速率
DOI：
10.1088/1674-1137/42/1/015001
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发表时间：
2018
影响因子：
3.6
通讯作者：
Liu Wei Ping
中科院分区：
文献类型：
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作者：
He Jian Jun;Lombardo Ivano;Dell'Aquila Daniele;Xu Yi;Zhang Li Yong;Liu Wei Ping
通过重新评估现有实验数据以及低能理论 R 矩阵外推法，得出了 0.007–10 GK 温度范围内的热核 19F (p, α0) 16O 反应速率。尽管所有利率在不确定性范围内都是一致的，但与之前的结果相比，我们的新利率偏差高达约 30%。在非常低的温度（例如 0.01 GK）下，我们的反应速率比最近发布的速率低约 20%，这是由于低能量外推 S 因子的差异以及在反应速率计算中使用的减少质量的更准确估计。在温度高于 ~ 1 GK 时，我们的速率较低，例如，在 1.75 GK 左右降低约 20%，因为我们仔细地重新评估了以前的数据 (Isoya et al., Nucl. Phys. 7, 116 (1958))。目前的解释得到了直接实验数据的支持。在0.2 GK以下的温度区域，目前评估速率的不确定性估计约为20%，这主要是由于低能实验数据的缺乏以及现有数据的不确定性较大造成的。渐近巨星分支（AGB）恒星在低于 0.2 GK 的温度下演化，其中 19F (p, α) 16O 反应可能发挥非常重要的作用。然而，目前反应速率的准确性不足以帮助仔细描述 AGB 恒星中观察到的氟过量现象。因此，天体物理核合成研究需要低能量区域的精确横截面（或 S 因子）数据。
The thermonuclear 19F (p, α0) 16O reaction rate in the temperature region 0.007–10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical R-matrix extrapolations. Our new rate deviates by up to about 30% compared to the previous results, although all rates are consistent within the uncertainties. At very low temperature (eg 0.01 GK) our reaction rate is about 20% lower than the most recently published rate, because of a difference in the low energy extrapolated S-factor and a more accurate estimate of the reduced mass used in the calculation of the reaction rate. At temperatures above∼ 1 GK, our rate is lower, for instance, by about 20% around 1.75 GK, because we have re-evaluated the previous data (Isoya et al., Nucl. Phys. 7, 116 (1958)) in a meticulous way. The present interpretation is supported by the direct experimental data. The uncertainties of the present evaluated rate are estimated to be about 20% in the temperature region below 0.2 GK, and are mainly caused by the lack of low-energy experimental data and the large uncertainties in the existing data. Asymptotic giant branch (AGB) stars evolve at temperatures below 0.2 GK, where the 19F (p, α) 16O reaction may play a very important role. However, the current accuracy of the reaction rate is insufficient to help to describe, in a careful way, the fluorine over-abundances observed in AGB stars. Precise cross section (or S factor) data in the low energy region are therefore needed for astrophysical nucleosynthesis studies.