Ionization Energies of Ions in Hot and Dense Plasma: Beryllium-Like Ions for Z=26-36

Ionization energies of beryllium-like ions for Z=26-36 in hot and dense plasmas (n_e=10²²-10²⁴cm^-3, kT=500-2000eV) are obtained by using an approach developed for electronic structure and transition property of ions in hot and dense plasmas based on the multi-configuration Dirac--Fock model. Influence of the plasma environment is considered by introducing a correction to the one-electron potential to account for the screening of the ionized electrons. This correction is calculated from the ionized electron micro-space distribution, which is obtained based on an average atom model for the temperature and density-dependent average ionization of atoms in plasmas. Comparison between the present and the ion sphere models is made to display the significance of the ionized electron micro-space distribution.