On temperature dependence of the optical potential for alpha-particles at low energies

Within the double folding formalism of the α-nucleus optical potential, used previously for a semi-microscopic analysis of the α-particle elastic scattering on A∼100 nuclei at energies below 32 MeV, effects due to changes of the nuclear density at a finite temperature are considered. Parameterizations of the double-folding (DF) real potential as well as of a regional phenomenological potential have been used in the study of the (n,α) reaction cross sections for the target nuclei 92,95,98,100Mo. Taking into account the microscopic DF potentials based on nuclear density distributions, we are able to fully describe the excitation functions of the (n,α) reactions. It is shown that the temperature dependence of the nuclear density distribution function can be an important aspect that has to be included in statistical model calculations even for a nuclear temperature smaller than 2 MeV.