The Be-7 (p, gamma) B-8 cross section at low energies
The Be-7 (p, gamma) B-8 cross section at low energies
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低能量下的 Be-7 (p, gamma) B-8 截面
DOI：
10.1071/ph800177a
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
F. C. Barker
中科院分区：
文献类型：
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作者：
F. C. Barker
用直接俘获势模型重新计算了低能下7Be（p，n）I）8B截面的非共振部分，参数值由7Li（n，n）7Li和7Li（n，n）I）8Li数据拟合而得.电位参数和光谱因子的标准值给出了太大的7Li（n，I）截面值。修正后的值，适合热中子俘获截面预测7Be（p，）I）的截面比实验值小得多。此外，壳模型计算预测的共振7Be（p，）I）的横截面小于实验值。这表明，可接受的实验值的7Be（p，）I）截面可能太大，也许部分是由于过大的接受值的7Li（d，p）8Li截面，已被用于归一化的目的。7Be（p，I）截面的减小将降低太阳中微子的探测率，减小与测量值的偏差。
The nonresonant part of the 7Be(p, )I)8B cross section at low energies is recalculated by means of a direct-capture potential model, using parameter values determined by fitting 7Li(n, n)7Li and 7Li(n, )I)8Li data. Standard values of the potential parameters and spectroscopic factors give values of the 7Li(n,)I) cross section that are too large. Modified values that fit the thermal-neutron capture cross section predict 7Be(p,)I) cross sections that are much less than the experimental values. Also, shell model calculations predict resonant 7Be(p,)I) cross sections that are smaller than the experimental values. It is suggested that the accepted experimental values of the 7Be(p, )I) cross section may be too large, perhaps due partly to an overlarge accepted value for the 7Li(d, p)8Li cross section, which has been used for normalization purposes. A decrease in the 7Be(p,)I) cross section would reduce the calculated detection rate of solar neutrinos and lessen the discrepancy with the measured value.