Semi-classical calculations of hot nuclei

We present semi-classical calculations of hot nuclei performed within the framework of the procedure recently introduced by Bonche, Levit and Vautherin in Hartree-Fock calculations, in order to take consistently into account the effects of continuum states. We use zero and second order Thomas-Fermi approximations for describing the kinetic and spin-orbit energies. After having introduced the ingredients of the formalism and given the main features of our resolution scheme of the Thomas-Fermi equations, we perform a detailed comparison of our calculations with Hartree-Fock results in order to test the accuracy of our model. We discuss the zero-temperature limit case where T2 developments can be worked out. We show that, at low temperatures (T≤2 MeV) the subtraction procedure is not indispensable, as expected from Hartree-Fock calculations. We also recall recent results obtained by using our formalism in estimating the temperature dependence of the level density parameter. As in Hartree-Fock calculations we find the existence of a limiting temperature Tlim beyond which the nucleus is unstable because of the Coulomb interaction. By comparing our theoretical values of Tlim with recent experimental data, we show that, in spite of the approximation in our model, this limiting temperature could be related to actual disappearance of fusion-like processes in medium energy heavy-ion collisions. (orig.)