Ionization Equilibrium and Partition Functions of High-Temperature Weakly Nonideal Flibe Gas

A model for the ionization equilibrium of weakly non-ideal Flibe plasma is presented in terms of a set of coupled nonlinear Saha equations supplemented by electro-neutrality and conservation of nuclei. Non-ideality effects have been taken into account in terms of lowering of the ionization potentials and truncated partition functions. A simple formulation and solution strategy of the Saha equations for the single element case has been extended to apply for the case of plasma mixtures and has been used to calculate the composition of partially ionized Flibe plasma over a wide range of temperatures and densities. A criterion for the validity of the assumption of local thermodynamic equilibrium is presented and applied to the result. Effects of non-ideality corrections and approximating the partition function to the statistical weight of the ground state have been quantified and presented.