Various Modifications to Debye-Hückel Interactions in Solar Equations of State

Abstract

The first-order effect of Coulomb forces between the charged particles of a plasma is the well-known Debye-Hückel-term. This term represents a negative contribution to the pressure and energy of the gas, which at high densities could overwhelm the ideal gas contributions and make the gas implode into a black hole. However, this fate could be prevented by specific physical mechanisms. We investigate three different mechanisms and analyze their effects on the equation of state and solar models, as well as their physical justifications. We conclude that higher-order Coulomb terms, in combination with quantum diffraction of electrons, provide the needed convergence.