Nuclear Level Density according to Fermi-Gas and Constant Temperature Models*

The knowledge of the nuclear level density is necessary for many practical applications including astrophysical reactions. In this work we investigate phenomenological approaches to the level density, including popular models, such as Fermi-Gas, Back-Shifted Fermi-Gas and Constant Temperature. We compare the level densities obtained in these models with the Shell Model calculations. The main goal of the study is to estimate the parameters of phenomenological models and justify their status as reliable tools for realistic applications.