利用镜像核转移反应研究短寿命不稳定核(p,γ)反应

Study of (p,γ) Reactions on Short-Lived Nuclei Using Transfer Reaction of Mirror Nuclei

介绍利用中子转移反应和镜像核的电荷对称性来间接研究丰质子核的(p,γ)反应。该方法有助于更充分地利用北京HI-13串列加速器次级束流线(GIRAFFE)上现有次级束流,拓宽其实验研究范围,间接得出质子辐射俘获截面(或反应率)且减小其不确定性(相对于已有数据)。在GIRAFFE上利用逆运动学测量了8Li(d,p)9Li反应的角分布,通过该方法间接确定了天体物理重要反应8B(p,γ)9C的直接俘获贡献。作为不同于以往的方法,给8B(p,γ)9C反应的现有研究结果提供了一独立的交叉检验。分析26Mg(d,p)27Mg反应基态、第一、第二激发态的角分布,间接确定26Si(p,γ)27P反应的直接和共振俘获贡献,首次从实验上导出26Si(p,γ)27P反应的直接俘获贡献。此方法也可以用于其它一系列重要的天体物理反应的研究。

An indirect method that using neutron transfer reaction and charge symmetry of mirror nuclei, was introduced to study （p,γ） reactions on proton rich nuclei. It can contribute to the good use of radioactive secondary ion beams produced by GIRAFFE, the secondary beam facility at HI-13 tandem accelerator, and indirectly extract the proton capture cross section which has not been available to date or reduce its uncertainty （compared with the preexisting results）. We measured the ^8 Li（d, p）^9 Li angular distribution in inverse kinematics at GIRAFFE, and then derived the contribution of direct capture in ^8B（p,γ）^9C through this indirect approach. This work provides an lnaependent examination to the existing results for^8 B（p, γ）^9 C. In addition, we reanalyzed the angular distributions of ^26 Si （p, γ）^27 p leading to the ground, the first and the second excited states of ^27p, and then indirectly extracted the contribution of direct and resonant captures in ^26Si （p, γ）^27p. The direct capture contribution is experimentally obtained for the first time. The approach described here can be also used for the study of many reactions of astrophysical importance.