(n,p)和(n,α)激发函数半经验计算方法  

Semi-empirical Method for (n, p) and (n, α) Reactions' Excitation Function

作　　者：樊胜[1] 阎芳[1] 张鸿洲[1] 赵志祥[1] 

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》2004年第4期389-390,397,共3页Nuclear Physics Review

基　　金：国家重点基础研究发展规划资助项目(G1999022600);国家自然科学基金资助项目(10305021)~~

摘　　要：在En≤20MeV的情况下,忽略了粒子的二次发射过程,认为复合系统的形成截面是能量相关的,得到了理论模型清晰、公式形式简单的半经验计算方法.在靶核23≤A≤209的范围内,利用大量(n,p)和(n,α)反应的截面实验数据对可调参数进行了研究,得到了参数对靶核的N和Z以及入射能量的依赖关系.对得到的参数做了定性的解释,利用普适参数对(n,p)和(n,α)反应的激发函数做了预言,预言值在其误差范围内与实验数据一致.To simplify the calculation, some assumptions are considered at present work. The preequilibrium emission is the first step in the equilibrium process, which is characterized by exciton n=3 and 'never come back' are considered at the preequilibrium emission process; the proton and alpha emissions are only competed with the neutron emission, the second particle emission is neglected. A semiempirical method of the cross section for (n, p ) and (n, α) reactions were obtained on the basis of evaporation and exciton models in the energy range up to 20 MeV. A strong dependence on (N-Z+1)/A and the incident energy has been observed for 23≤A≤209. The predictions of the semi-empirical systematics with the global parameter of the excitation functions for (n, p ) and (n, α) reactions are in good agreement with the experimental data.

关 键 词：激发函数 半经验计算 入射能 截面 实验数据 可调参数 粒子 反应 方法 能量 

分 类 号：O571[理学—粒子物理与原子核物理] O641.1[理学—物理]