Nuclear shell gaps at finite temperatures

Abstract:

Neutron–rich nuclei with a closed neutron shell represent chains of waiting–point nuclei in the astrophysical r–process. Details of their nuclear structure like separation energies, shell structure and β⁻–decay half–lives have a dramatic influence on element abundances calculated from r–process simulations. Actual supernova scenarios take place at finite temperature. To investigate the influence of finite temperature on binding energies and shell gaps, i.e. the second derivative of the binding energy, we calculate the shell gaps in the range of interest and slightly beyond, i.e. 0 ≤k _B T≤ 0.8 MeV. Basis of the description is the self–consistent Skyrme–Hartree–Fock model and an extension of BCS pairing to finite temperature using a natural orbital representation.