利用^(18)O(~6Li,d)^(22)Ne反应研究^(22)Ne E_α=470 keV共振态的性质  

Study of the E_α= 470 keV Resonance in ^(22)Ne via ^(18)O(~6Li,d)^(22)Ne Reaction

作　　者：苏毅 曾晟[1] 李云居[1] 王友宝[1] 李志宏[1] 郭冰[1] 苏俊[1] 颜胜权[1] 樊启文[1] 甘林[1] 韩治宇[1] 李鑫悦 连钢[1] 刘建成[1] 马田丽 谌阳平 周勇[1] 柳卫平[1] SU Yi;ZENG Sheng;LI Yunju;WANG Youbao;LI Zhihong;GUO Bing;SU Jun;YAN Shengquan;FAN Qiwen;GAN Lin;HAN Zhiyu;LI Xinyue;LIAN Gang;LIU Jiancheng;MA Tianli;SHEN Yang ping;ZHOU Yong;LIU Weiping(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院

出　　处：《原子核物理评论》2018年第4期450-454,共5页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(11475265)~~

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。^(22)Ne(α, n)^(25)Mg反应是大质量AGB星中s过程主要的中子源,其中的^(22)Ne主要通过14N(α,γ)18F(β+)18O(α,γ)^(22)Ne反应链合成。该反应链中关键反应18O(α,γ)^(22)Ne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^(22)Neα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)^(22)Ne反应的角分布,利用DWBA分析确定了^(22)Ne分离阈附近共振能级Eα=470 ke V的自旋宇称为0+,为后续计算18O(α,γ)^(22)Ne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)25 Mg reaction as one of the main neutron sources. In the beginning phase of AGB thermal pulse,22Ne is produced by the14 N(α, γ)18 F(β+)18 O(α, γ)22Ne reaction sequence, in which the18 O(α, γ)22Ne reaction plays a key role. While the reaction rate of the18 O(α, γ)22Ne is mainly affected by several resonant states lying closely to the α threshold in22Ne, up to now, the relevant22Ne parameters are fragmentary in the energy region corresponding to the typical temperatures of s-process. The direct measurement of the18 O(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 the18 O(6 Li, 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 of22Ne Eα=470 ke V resonant states was assigned as 0+, which would make contributions to subsequent calculation for the reaction rate of the18 O(α, γ)22Ne.

关 键 词：s过程 HI-13串列加速器 能级参数 

分 类 号：O571.53[理学—粒子物理与原子核物理]