超重核合成截面计算中几个问题的探讨  

Approach Synthesis of Superheavy Nuclei from Some Aspects of Cross Section Calculations

作　　者：刘祖华[1] 

机构地区：[1]兰州重离子加速器国家实验室原子核理论中心

出　　处：《原子核物理评论》2003年第2期91-95,共5页Nuclear Physics Review

基　　金：国家重点基础研究发展规划基金资助项目(G2000077406);国家自然科学基金资助项目(10275092;10275095;10235030)

摘　　要：讨论了超重核形成截面计算中的耦合道效应、壳效应的阻尼效应、能级密度的集体运动增强因子以及蒸发残余核的自旋分布等几个重要问题,并给出相应的实验结果.因这些因素都可能对截面有数量级的影响,正确处理与否直接关系到超重核合成截面理论预言的可靠性.Several important aspects in the cross section calculations for the synthesis of superheavy nuclei have been inquired. They are the effects of the coupledchannels, the damping of shell correction energy, the collective enhancements in the level density and the spin distributions of evaporation residues. The channel coupling of relative motion with internal degrees of freedom will enhance significantly the capture cross section at subbarrier energies. However, recent measurements of spin distributions for the survived compound nucleus show that only low partial waves contribute to the evaporation residues, which should at least partially cancel out the enhancement due to the effects of the channel coupling. The fission barriers are determined mainly by the shell correction energy in the case of superheavy nuclei. Therefore, it is especially important to determine as accurate as possible the damping parameter which describes the decrease of the shell effects influence. In addition, the collective enhancement factor in the level density also plays a very important role in the synthesis of heavy spherical nuclei.

关 键 词：超重核合成 超重元素 原子核物理 截面计算 耦合道效应 壳效应 阻尼效应 能级密度 集体运动增强因子 蒸发残余核 自旋分布 

分 类 号：O571.6[理学—粒子物理与原子核物理]