Collision integrals and viscosity coefficients of argon–carbon thermal plasmas: Comparison using different interaction potentials

Abstract

The calculated values of collision integrals of the majority of binary interactions that can be involved in argon/carbon (Ar/C) plasmas are presented in this work. The studied plasmas are considered to be in local thermodynamic equilibrium, and calculations are performed from 1000 to 30 000 K. Computations have been carried out first for standard potentials and second for the Improved Lennard-Jones (ILJ) potential. In this paper, a clear and well detailed report is given for each methodology adopted to calculate the omega integrals, together with the main data needed to perform these computations. The obtained values of collision integrals have been compared with some data reported in the literature, and then, they are used to estimate the viscosity of two plasma systems, namely, pure argon and a mixture of argon and carbon (Ar/C). The calculation of viscosity coefficients is made on the basis of the Chapman–Enskog method and developed to the first approximation. The important contribution of the charge exchange process and its influence on the accuracy of the diffusion-type collision integrals of neutral–parent ion systems are emphasized. Although some discrepancies are observed, comparisons of our results with those of previously published studies show an overall satisfactory agreement in most of the cases. Our investigation of the data uncertainty further confirms the suggestion that the ILJ approach is an excellent candidate to provide collision integrals with acceptable accuracy when reliable experimental data or accurate theoretical calculations are unavailable. For that, all the necessary collision integrals needed to calculate reliable transport properties of the Ar/C plasma mixtures are reported in this work.