Bound states in nonideal plasmas: formulation of the partition function and application to the solar interior

Abstract

A detailed independent derivation of the hydrogen weakly nonideal plasma equation of state (EOS) is presented. In our computations relativistic corrections, degeneracy of electrons, radiation pressure in the plasma, Coulomb interaction in the Debye–Hückel approximation together with diffraction and exchange corrections and the contribution of bound and scattering states (SS) are taken into account. In contrast to the Planck–Larkin partition function, a correct separate account of bound and SS allows a natural generalization for the broadening of atomic states.The essential part of the EOS and adiabatic exponent is connected with the correct account of bound states. In our paper we compare the results of different approaches with the bound states description and for the first time consider the influence of atomic states broadening on the bound states contribution.