Nuclear Level Density at Finite Temperatures

Abstract

Selfconsistent mean-field calculations have been performed with the SkM* Skyrme force for 140 spherical even-even nuclei at temperatures 0 ≤ T ≤ 4 MeV. Single-particle level densities for this sample of nuclei are determined for various temperatures. The average dependence of the single-particle level density on mass number A and isospin is given and compared with previous estimates obtained using the relativistic mean-field and different semiclassical approaches.a Two of us (B.N.P. and K.P.) are very grateful for the warm hospitality extended to them by the Nuclear Theory Groups of the IReS in Strasbourg. J.B., in turn, gratefully acknowledges several fruitfull visits to the UMCS in Lublin. This work was partially supported by the IN2P3-Polish Laboratories Convention, Project No. 99-95 and Polonium grant (2005). 478 Int. J. Mod. Phys. E 2006.15:478-483. Downloaded from www.worldscientific.com by MCMASTER UNIVERSITY on 02/06/15. For personal use only.

A Laplace-like formula for the energy dependence of the nuclear level density parameter

“…In the early studies of the level density, the level density parameter was taken to consist of only its asymptotic value, therefore, it was independent of the excitation energy. This parameter is usually deduced from the experimental data by using a parameterized equation [20][21][22] as well as it can be calculated theoretically from the proton and neutron single-particle level densities at corresponding Fermi energies…”

Level-density parameters in superheavy nuclei

“…In contrast, a self-consistent meanfield approach is utilized to determine single-particle level densities at various temperatures and the level density parameters are calculated using the Yukawa-folded potential in Ref. [9]. Spin-and parity-dependent nuclear level densities obtained with the moment method in the proton-neutron formalism are presented in Ref.…”