Expectations for {sup 12}C and {sup 16}O induced fusion cross sections at energies of astrophysical interest
Expectations for {sup 12}C and {sup 16}O induced fusion cross sections at energies of astrophysical interest
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DOI：
10.1103/physrevc.75.015803
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发表时间：
2007-01
影响因子：
3.1
通讯作者：
C. Jiang;K. Rehm;B. Back;R. Janssens
中科院分区：
文献类型：
--
作者：
C. Jiang;K. Rehm;B. Back;R. Janssens
重新考察了由{sup 12}C和{sup 16}O核参与的聚变反应的截面外推到与恒星爆炸燃烧有关的能量。基于对较重系统聚变的系统研究，由于核物质的饱和性质，预计在极亚势垒能量下，聚变过程也将在这些轻重离子系统中被抑制。因此，以前基于光学模型计算的轻重离子聚变的S因子的唯象外推可能高估了相应的反应速率。考虑到阻碍行为，提出了一个新的‘’配方‘’来推断轻重离子向低能反应的S因子。它基于对实验截面的对数导数的拟合，与其他方法相比，该方法对不同数据集之间的整体归一化差异的敏感度要低得多。因此，这种方法比其他外推法有了很大的改进。讨论了它们对天体物理反应速率的影响。
The extrapolations of cross sections for fusion reactions involving {sup 12}C and {sup 16}O nuclei down to energies relevant for explosive stellar burning have been reexamined. Based on a systematic study of fusion in heavier systems, it is expected that a suppression of the fusion process will also be present in these light heavy-ion systems at extreme sub-barrier energies due to the saturation properties of nuclear matter. Previous phenomenological extrapolations of the S factor for light heavy-ion fusion based on optical model calculations may therefore have overestimated the corresponding reaction rates. A new ''recipe'' is proposed to extrapolate S factors for light heavy-ion reactions to low energies taking the hindrance behavior into account. It is based on a fit to the logarithmic derivative of the experimental cross section which is much less sensitive to overall normalization discrepancies between different data sets than other approaches. This method, therefore, represents a significant improvement over other extrapolations. The impact on the astrophysical reaction rates is discussed.