摘要
A dynamical Langevin model is employed to evaluate the excess of the neutron emission in the fission ofheavy nuclei ^(240)Cf,^(246)Cf,^(254)Cf,^(240)U relative to the standard statistical-model prediction at various saddle-to-scissionfriction strengths.It is shown that when the neutron-to-proton ratio N/Z of the system increases,the sensitivityof the excess to the friction decreases substantially,and it almost disappears for ^(240)U.We suggest that using thosecompound systems with low N/Z favors an accurate determination for the saddle-to-scission friction strength based onthe measurement of the pre-scission neutron multiplicity.
基金
Supported by the Foundation of Nanjing University of Finance and Economics under Grant No.C0836
