On Consistent Description of Nuclear Level Density

Abstract

The back–shifted Fermi gas (BSFG) model has been used for description of the nuclear level density at excitation energies up to the nucleon binding energy by fitting the latest experimental low–lying discrete levels and average s–wave nucleon resonance spacings D0. The analysis of the ratio of the proton and neutron resonance spacings corresponding to the same compound nucleus has led to the ratio IIr=(0.75±0.06) of the effective moment of inertia of the nucleus to the rigid-body value Ir for the nucleus 51V. The energy-dependent level density parameter and the method proposed by Koning and Chadwick for choosing the appropriate shell correction energy have been adopted for energies above the nucleon binding energy. Finally, a consistent description of all experimental data related to the nuclear level density, i.e. the low–lying discrete levels, the nucleon–resonance data, and the level density data above the nucleon binding energy, has been obtained for nuclei within A–ranges 24–41, 55–70, and 104–114.