Nuclear level density and thermal properties of ${}^{115}$Sn from neutron evaporation

Abstract

The nuclear level density of ${}^{115}$Sn has been measured in an excitation energy range of $\sim$2 - 9 MeV using the experimental neutron evaporation spectra from the ${}^{115}$In($p,n$)${}^{115}$Sn reaction. The experimental level densities were compared with the microscopic Hartree-Fock BCS (HFBCS), Hartree-Fock-Bogoliubov plus combinatorial (HFB+C), and an exact pairing plus independent particle model (EP+IPM) calculations. It is observed that the EP+IPM provides the most accurate description of the experimental data. The thermal properties (entropy and temperature) of ${}^{115}$Sn have been investigated from the measured level densities. The experimental temperature profile as well as the calculated heat capacity show distinct signatures of a transition from the strongly-paired nucleonic phase to the weakly paired one in this nucleus.

This article has been submitted to European Journal of Physics A for publication