原子核的对相互作用对裂变碎块角分布的影响

我们把Migdal的关于基态原子核转动惯量的半经典近似的推导,推广到激发态(T≠0)情形;并由此计算了裂变碎块角分布参数K₀²。与实验数据比较的结果表明:在现有近似下,原子核的对相互作用能解释U区裂变核在低激发能(E_exc≤15MeV)时,K₀²“反常”小的现象,同时利用对相互作用与角动量的依赖关系,可以定性地解释Pb附近裂变核并没有这种“反常”现象。

THE PAIRING EFFECTS OF NUCLEI ON THE ANGULAR DISTRIBUTION OF THE FISSION FRAGMENTS

The derivation of the moment of inertia for the ground state nucleus given by Migdal in the quasi-classical approximation has been extended to the excited state case, i.e. T≠0. We have calculated K₀² , the parameter of the angular distribution of the fission fragments. The results arc compared with the experimental data. This shows that under the present approximation the "anomalously" small K₀² of fissioning nuclei in the uranium region at low excitation energy (E_exc≤15 MeV) can be explained by introduction of the pairing effects in nuclei. Furthermore, the absence of the "anomalous" phenomena for fissioning nuclei near the lead region may be qualitatively interpreted by means of the dependence of pairing effects on angular momentum.