Applicability of the Hauser-Feshbach approach for the determination of astrophysical reaction rates

Nuclear Astrophysics requires the knowledge of reaction rates over a wide range of nuclei and temperatures. In recent calculations the nuclear level density – as an important ingredient to the statistical model (Hauser-Feshbach) – has shown the highest uncertainties. In a back-shifted fermi-Gas formalism utilizing an energy-dependent level density parameter and employing microscopic corrections from a recent FRDM mass formula, we obtain a highly improved fit to experimental level densities. The resulting level density is used for determining criteria for the applicability of the statistical model