摘要: 慢速中子俘获过程（s过程）是合成比铁重元素的重要途径之一。²²Ne（α，n）²⁵Mg反应是大质量AGB星中s过程主要的中子源，其中的²²Ne主要通过¹⁴N（α，γ）¹⁸F（β⁺）¹⁸O（α，γ）²²Ne反应链合成。该反应链中关键反应¹⁸O（α，γ）²²Ne在天体物理感兴趣能区的截面非常低，其天体反应率主要来自于²²Ne α分离阈附近低能共振态的贡献，但目前相关能级的共振参数严重缺失。在HI-13串列加速器的Q3D磁谱仪上，通过测量¹⁸O（⁶Li，d）²²Ne反应的角分布，利用DWBA分析确定了²²Ne分离阈附近共振能级E_α=470 keV的自旋宇称为0⁺，为后续计算¹⁸O（α，γ）²²Ne的天体反应率打下了基础。


About a half of the abundances of elements heavier than iron comes from the so-called slowneutron capture process (s-process) in Asymptotic Giant Branch (AGB) stars, with the ²²Ne(α, n)²⁵Mg reaction as one of the main neutron sources. In the beginning phase of AGB thermal pulse, ²²Ne is produced by the ¹⁴N(α, γ)¹⁸F(β⁺)¹⁸O(α, γ)²²Ne reaction sequence, in which the ¹⁸O(α, γ)²²Ne reaction plays a key role. While the reaction rate of the ¹⁸O(α, γ)²²Ne is mainly affected by several resonant states lying closely to the α threshold in ²²Ne, up to now, the relevant ²²Ne parameters are fragmentary in the energy region corresponding to the typical temperatures of s-process. The direct measurement of the ¹⁸O(α, γ)²²Ne reaction rate is extremely difficult due to the very low cross section. In this work, we investigated the ²²Ne resonant states via the ¹⁸O(⁶Li, d)²²Ne reaction at the Beijing HI-13 tandem accelerator of China Institute of Atomic Energy. Based on the DWBA analysis, preliminary results showed that the spin-parity of ²²Ne E_α=470 keV resonant states was assigned as 0⁺, which would make contributions to subsequent calculation for the reaction rate of the ¹⁸O(α, γ)²²Ne.