Basic chemical models of partially ionized plasma

Abstract

The concept of "basic chemical models" is introduced, which is new from the standpoint of the physics of nonideal atomic plasma. This concept is based on the requirement of full correspondence of the free energy of the chemical model (free electrons, ions and atoms) of plasma to the results of exact asymptotic expansions obtained in the grand canonical ensemble for the physical model (base electrons and nuclei) of plasma. The thermodynamic functions and equations of state and ionization equilibrium are obtained for three basic chemical models differing from one another by the choice of the atomic partition function. Comparison is made with the experimental results for a nonideal plasma of cesium and inert gases. It is demonstrated that the best fit to experiment is shown by the results obtained within a basic chemical model with atomic partition function in the nearest neighbor approximation with classical determination of the size of excited atom.

Calculation of the hydrogen plasma absorption coefficient using basic chemical models

“…Necessary expressions can be found in [1,2]. Here, we present only the relations between these quantities and P b (E n ):…”

“…Using (1)-(3), one can calculate the equation of state, lowering of the ionization energy and plasma composition allowing for the interaction of charged particles [2].…”

“…For calculation of composition and thermodynamic functions of plasma, numerous versions of the chemical model of plasma with different ways of the truncation of the atomic partition function and corrections due to interactions among free charges [1,2] are widely used. There are also several methods of calculation of the cross-sections of radiation processes, especially in the nearthreshold spectral region [3].…”