Preliminary analysis of neutron optical potential for A=40-60 below 10 MeV

The variation of the total cross section σt and the absorption cross section σa with the parameters of the spherical optical potential (SOP) at low neutron energies for the nuclei in the region of the maximum strength function (A=40∼60) has been studied. These results show that the dependence of σt and σa on the parameters of the SOP and neutron energy is very complicated. For the dependence of the cross section on the SOP, the real potential parameters are more sensitive than the imaginary potential ones, and the real potential depth V0 and real radius parameter rR are the most sensitive parameters in the SOP. The behaviours of the total cross section with varying SOP parameters depend strongly on the neutron energy and are very different for the different nuclei. The results have shown why the existing parametrizations do not give a good agreement with experimental data for low neutron energies in this mass region. The processes and results shown in this paper are significant to obtain the best parametrization for fitting the experimental data. (author). 18 refs, 27 figs