天体物理重要反应^(13)N(p,γ)^(14)O的实验研究

Experimental Study of ^(13)N(p,γ)^(14)O Reaction of Astrophysical Importance

13N(p,γ)14O是高温CNO循环中的关键反应,对恒星能量产生机制及其演化的研究具有重要意义。利用北京HI-13串列加速器次级束流线产生的13N放射性束测量了质心系能量为8.9 MeV的13N(d,n)14O反应的角分布,导出了14O基态渐进归一化系数(ANC)为(29.4±5.3)fm-1。此外,使用镜像核的电荷对称性,通过分析13C(d,p)14C反应的角分布,导出了与实验一致的14O基态质子ANC。使用最新开发出的R矩阵程序,导出13N(p,γ)14O反应在高温CNO循环中的天体物理S因子和反应率。将此数据代入核天体物理反应的网络程序进行计算,结果表明,新星中CNO循环产生的能量比原有的结果多5%,这可能会对新星的演化有一定的影响。

^13N（p,γ）^14O is one of the key reaction in hot CNO cycle, which is important for studying the energy source of evolution of stars. The angular distribution of ^13N（p,γ）^14O at Ecru = 8. 9 MeV was measured using ^13N beam produced by secondary beam facility at HI-13 tandem accelerator. The ANC of 140 was then extracted to be （29.4± 5.3） fm^-1. In addition, we derived the asymptotic normalization coefficient （ANC） of 140 by analyzing the 13C（d, p）14C angular distribution based on charge symmetry of mirror nuclei, which agrees with the experimental result. The astrophysical S factor and reaction rate of ^13N（p,γ）^14O were then calculated using R-matrix theory and were inputted into astrophysical reaction network. It shows the energy generated by CNO cycle in novae using the present data is 5% more than that using the previous ones, which could affect the evolution of novae.