沈彩万[2011PRC]:重离子反应中的熔合阻止:正常熔合和带有阻止
2020-11-29
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■ Fusion hindrance in reactions with very heavy ions: Border between normal and hindered fusion
重离子反应中的熔合阻止:正常熔合和带有阻止熔合的边界
作者:沈彩万, D. Boilley(法国), 李庆峰,沈军杰,Y. Abe(日本)
杂志:Phys. Rev. C 83, 054620 (2011)
摘要:利用双中心液滴模型,我们研究了重离子反应中的熔合阻止现象。结果显示,在重核从接触到复合核形成的过程中,颈部自由度和径向自由度可能会同时遇到由于内侧位垒引起的熔合阻止。通过系统计算,带有和不带有熔合阻止的反应被区别开来。计算表明,没有径向熔合阻止的反应数目远低于没有颈部熔合阻止的反应数目。并且对于这两种熔合阻止,非对称系数较大时所包含的无熔合阻止反应数大于非对称系数较小时所包含的熔合阻止数。对于复合核给定的反应,如果对应于某一非对称系数αc的反应不存在熔合阻止,则对所有非对称系数大于αc的反应也不存在熔合阻止。
Abstract: The fusion hindrance in heavy-ion collisions is studied in the framework of the two-center liquid drop model. It appears that the neck and the radial degrees of freedom might both be hampered by an inner potential barrier on their path between the contact configuration to the compound nucleus. Heavy-ion reactions with and without the two kinds of fusion hindrance are classified through systematic calculations. It is found that the number of reactions without radial fusion hindrance is much smaller than that without neck fusion hindrance, and for both kinds of fusion hindrance the number of reactions without fusion hindrance at small mass-asymmetry parameter α is smaller than that at large α. In the formation of a given compound nucleus, if a reaction with αc is not hindered, then other reactions with α>αc are also not hindered, as is well known experimentally.