Simple formulation and solution strategy of the Saha equation for ideal and nonideal plasmas

A simple formulation and solution strategy for the Saha equation is introduced. The formulation discriminates between the cases in which either the pressure or the number density of heavy particles is known. This discrimination allows the method to be generalized to include all problems of practical interest, as well as to clarify ambiguities found in other formulations in the literature. The present method overcomes restrictions imposed on other competitive techniques and takes into account all possible formulae for nonideality corrections. In most practical cases the solution of the nonlinear set of the Saha equations is reduced to the simple problem of solving a single transcendental equation.