质子滴线核在近垒能区的反应机制研究进展  

Progress of Studies on Reaction Dynamics Induced by Proton Drip-line Nuclei at Energies Around the Coulomb Barrier

作　　者：尹诚 杨磊[1] 林承键[1] 马南茹[1] 贾会明[1] 温培威 杨峰[1] 骆天鹏 常昶 黄志杰 段海锐 杨炅和 YIN Cheng;YANG Lei;LIN Chengjian;MA Nanru;JIA Huiming;WEN Peiwei;YANG Feng;LUO Tianpeng;CHANG Chang;HUANG Zhijie;DUAN Hairui;YANG Jionghe(China Institute of Atomic Energy,Beijing 102413)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《原子核物理评论》2024年第1期141-147,共7页Nuclear Physics Review

基　　金：国家重点研发计划项目(2022YFA1602302);国家自然科学基金资助项目(U2167204,12175314,12235020)。

摘　　要：质子滴线核在近垒能区的反应机制,尤其是破裂机制,是当前核物理领域的前沿热点问题。为了深入考察质子滴线核的反应动力学,基于日本东京大学的CRIB终端开展了^(8)B+^(120)Sn和^(17)F+^(58)Ni体系在近垒能区的完全运动学测量。本工作在综述前期研究结果的基础上,首次展示了^(8)B+^(120)Sn测量中的熔合截面结果。实验设置方面,针对各自反应体系产物的特点,分别设计了高效率的硅探测器阵列STARE和基于电离室的多层望远镜阵列MITA,实现了反应产物的完全鉴别。对于质子晕核8B+120Sn体系首次实现了破裂碎片的符合测量,重构了完整的破裂过程,揭示了^(8)B出射道瞬时破裂为主的弹性破裂机制。对于质子滴线核^(17)F+^(58)Ni体系则首次实现了全反应道测量,提取了准弹、破裂和总熔合反应的信息,并发现在垒下能区存在熔合截面增强的现象。理论分析表明,这主要是由于破裂连续态的耦合效应所导致,并且8B和17F存在不同的直接反应机制,表明质子晕结构对反应机制存在显著影响。Reaction dynamics,especially the breakup mechanisms,induced by proton drip-line nuclei at energies around the Coulomb barrier,is one of the most popular topics in nuclear physics.In order to further investigate the reaction mechanisms of proton drip-line nuclei,we performed the complete-kinematics measurements of ^(8)B+^(120)Sn and ^(17)F+^(58)Ni at CRIB,University of Tokyo.This paper summarizes our research findings and unveils for the first time the fusion cross-section results in the 8B+120Sn measurement.Two detector arrays,i.e.,the silicon telescope array of STARE and the ionization chamber array of MITA,were designed respectively for the measurements of ^(8)B and ^(17)F.Reaction products were completely identified with the help of these two arrays.For the 8B+120Sn system,the coincident measurement of the breakup fragments was achieved for the first time.The correlations between the breakup fragments reveal that the prompt breakup occurring on the outgoing trajectory dominates the breakup dynamics of 8B.For 17F+58Ni,the complete reaction channel information,such as quasi-elastic scattering,breakup and total fusion,was derived for the first time.An enhancement of the fusion cross section of ^(17)F+^(58)Ni was observed at the energy below the Coulomb barrier.Theoretical calculations indicate that this phenomenon is mainly due to the coupling to the continuum states.Moreover,different direct reaction dynamics were found in ^(8)B and ^(17)F systems,suggesting the influence of proton-halo structure on the reaction dynamics.

关 键 词：质子滴线核 库仑势垒能区 反应机制 

分 类 号：O571.53[理学—粒子物理与原子核物理]