基于熔合蒸发反应的超重新元素Z=119,120的产生截面  

Production Cross-sections of New Superheavy Elements with Z=119,120 in Fusion-evaporation Reactions

作　　者：王子涵 陈鹏辉 曾祥华 冯兆庆 WANG Zihan;CHEN Penghui;ZENG Xianghua;FENG Zhaoqing(College of Physical Science and Technology,Yangzhou University,Yangzhou 225009,Jiangsu,China;Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;College of Electrical,Power and Energy Engineering,Yangzhou University,Yangzhou 225009,Jiangsu,China;School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]扬州大学物理与科学技术学院,江苏扬州255009 [2]中国科学院近代物理研究所,兰州730000 [3]扬州大学电气与能源动力工程学院,江苏扬州255009 [4]华南理工大学物理与光电学院,广州510641

出　　处：《原子核物理评论》2022年第4期421-433,共13页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(12105241,12175072);江苏省自然科学基金资助项目(BK20210788);江苏省双创博士资助项目(JSSCBS20211013);江苏省教育厅高校面上资助项目(21KJB140026);扬州市绿扬金凤优秀博士资助项目(YZLYJFJH2021YXBS130);中国科学院近代物理研究所高精度核谱学重点实验室开放课题(IMPKFKT2021001)。

摘　　要：基于双核系统模型,系统计算了熔合蒸发反应^(48)Ca+^(22)Es,^(48)Ca+^(257)Fm,^(49)Sc+^(252)Es,^(49)Sc+^(251)Cf,^(50)Ti+^(247)Bk,^(50)Ti+^(251)Cf,^(51)V+^(247)Cm,^(51)V+^(247)Cf,^(54)Cr+^(243)Am,^(54)Cr+^(247)Cm,^(56)Mn+^(244)Pu,^(56)Mn+^(243)Am,^(60)Fe+^(237)Np,^(60)Fe+^(244)Pu,^(61)Co+^(238)U,^(61)Co+^(237)Np,^(64)Ni+^(231)Pa,^(64)Ni+^(238)U,^(65)Cu+^(232)Th,^(65)Cu+^(231)Pa,^(68)Zn+^(232)Th中的超重新核素Z=119,120产生截面。从驱动势中提取内部熔合位垒,结合势能面可以用于粗略地预测熔合几率相对值。还系统研究了碰撞系统不对称度对超重新元素合成的影响,发现超重核合成截面随着反应系统的质量不对称度增加而增大。^(46-50)Ti诱发的熔合蒸发反应有利于合成新超重元素Z=119~120。还讨论了弹核同位旋对超重新元素合成截面的影响。计算表明,合成超重新元素^(28-295)119的最佳弹靶组合为^(44,46,48.50)T1+^(247)Bk,合成截面约为一皮靶,反应道为(2~4)n,激发能为20~40 MeV。在激发能26 MeV的^(46)Ti(^(251)Cf,2n)^(295)120反应中,合成新元素^(295)120的最大截面约为一皮靶。基于本工作的计算,提出了合成超重新元素Z=119~120最佳的弹靶组合和反应能量,为未来的相关实验提供参考。We have calculated production cross sections of new superheavy elements with atomic number Z=119,120 in the fusion-evaporation reactions of^(48)Ca+^(252)Es,^(48)Ca+^(257)Fm,^(49)Sc+^(252)Es,^(49)Sc+^(251)Cf,^(50)Ti+^(247)Bk,^(50)Ti+^(251)Cf,^(51)V+^(247)Cm,^(51)V+^(247)Cf,^(54)Cr+^(243)Am,^(54)Cr+^(247)Cm,^(56)Mn+^(244)Pu,^(56)Mn+^(243)Am,^(60)Fe+^(237)Np,^(60)Fe+^(244)Pu,^(61)Co+^(238)U,^(61)Co+^(237)Np,^(64)Ni+^(231)Pa,^(64)Ni+^(238)U,^(65)Cu+^(232)Th,^(65)Cu+^(231)Pa,and^(68)Zn+^(232)Th within the dinuclear system model systematically.The inner fusion barriers have been extracted from the driving potential and potential energy surface which could be used to predict the relative fusion probability roughly.The influence of mass asym-metry of the colliding partners on the production of new superheavy elements(SHE)has been investigated systemat-ically.It is found that fusion probability increases along with the increasing mass asymmetry of colliding systems.The 4650Ti-induced reactions prefer to produce new SHE with Z=119~120.The dependence of production cross-sec-tions of new superheavy elements on the isospin of projectile nuclei has been discussed.The new SHE of 289293119.has been predicted as the synthesis cross sections around one picobarn in the ^(44,46,48,50)Ti-induced reactions.Produc-tion cross-section of the element 295120 has been evaluated as large as one picobarn in the reactions^(46)Ti(^(251)Cf,2n)^(295)120 at E*=26 MeV.The optimal projectile-target combinations and beam energies for producing new SHE with atomic number Z=119~120 are proposed for the forthcoming experiments.

关 键 词：超重新元素 合成截面 入射道效应 双核模型 

分 类 号：O571.6[理学—粒子物理与原子核物理]