Properties of warm nuclei in the quasi-continuum

Nuclear thermodynamic quantities are extracted from nuclear level densities measured with the CACTUS detector array at the Oslo Cyclotron Laboratory. The experiments are performed with light-particle inelastic or transfer reactions. A simple combinatorial model is used to describe the underlying mechanisms responsible for the exponential increasing level density as function of excitation energy. The calculated number of broken Cooper pairs and the parity distribution in continuum are discussed. An overall agreement with data supports the schematic underlying physics of the model. We find that the breaking of Cooper pairs is the most effective way to create many levels. For odd-A nuclei, the single particle outside the even-even core creates about 5 times more levels. The breaking of a Cooper pair introduces about 5*5=25 more levels. In comparison, the collective part (rotation and vibrations) is only responsible for a factor of 5 or less