Level density within a micro-macroscopic approach

Abstract

Statistical level density ρ(E,A) is derived for nucleonic system with a given energy E, particle number A and other integrals of motion in the micro-macroscopic approximation beyond the standard saddle-point method of the Fermi gas model. This level density reaches the two limits; the well-known Fermi gas grand-canonical ensemble limit for a large entropy S related to large excitation energies, and the finite micro-canonical limit for a small combinatorical entropy S at low excitation energies. The inverse level density parameter K as function of the particle number A in the semiclassical periodic orbit theory, taking into account the extended Thomas-Fermi and Strutinsky shell corrections, is calculated and compared with experimental data.