The reactions ${}^{6,7}\mathrm{Li}+{}^{27}\mathrm{Al}$ were compared with the reactions ${}^{17,18}\mathrm{O}+{}^{16}\mathrm{O}$ which form the same compound nuclei ${}^{33,34}\mathrm{S}$. Cross-section data for the reactions ${}^{6,7}\mathrm{Li}+{}^{27}\mathrm{Al}$ were derived from experimentally determined γ-ray production cross sections for transitions in several residual nuclei. For the reactions ${}^{17,18}\mathrm{O}+{}^{16}\mathrm{O}$ experimental results from the literature were used. It could be shown that the weakly bound projectiles ${}^{6,7}\mathrm{Li}$ undergo not only fusion processes, but also breakup reactions quite in contrast to the tightly bound projectiles ${}^{18}\mathrm{O}$ and ${}^{17}\mathrm{O}$, respectively. Especially below the Coulomb barrier such direct reactions play an important role in competition to complete fusion. Calculations based on the statistical model agree well with the available data for ${}^{17,18}\mathrm{O}+{}^{16}\mathrm{O}$, but failed to represent the behavior of the experimentally determined production cross sections for the evaporation residues in the reactions ${}^{6,7}\mathrm{Li}+{}^{27}\mathrm{Al}$. But coupled-channel codes and calculations based on a nucleus-nucleus proximity potential are able to reproduce the energy dependence of the complete fusion cross sections.

中文翻译：

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Li6,7+Al27 接近和低于库仑势垒的反应

反应 ${}^{6,7}李+{}^{27}铝$ 与反应进行了比较 ${}^{17,18}\mathrm{哦}+{}^{16}\mathrm{哦}$ 形成相同的复合核 ${}^{33,34}\mathrm{秒}$. 反应的横截面数据${}^{6,7}李+{}^{27}铝$来自实验确定的γ射线产生截面，用于几个残余核中的跃迁。对于反应${}^{17,18}\mathrm{哦}+{}^{16}\mathrm{哦}$使用了文献中的实验结果。可以证明弱束缚弹丸${}^{6,7}李$ 不仅经历融合过程，而且与紧密结合的射弹形成鲜明对比的是分裂反应 ${}^{18}\mathrm{哦}$ 和 ${}^{17}\mathrm{哦}$， 分别。特别是在库仑势垒以下，这种直接反应在完全聚变的竞争中起着重要作用。基于统计模型的计算与可用数据非常吻合${}^{17,18}\mathrm{哦}+{}^{16}\mathrm{哦}$，但未能代表反应中蒸发残留物的实验确定的生产横截面的行为 ${}^{6,7}李+{}^{27}铝$. 但是基于核-核邻近势的耦合通道代码和计算能够再现完整聚变截面的能量依赖性。