International Journal of Physics | Vol. 7, No. 7, July 2016 | pp. 49–56
DOI: 10.46882/2016/IJP/000075
Research Article
Title: Kinetic Simulation of Electron Transport and Excitation Rates in Low-Pressure Helium-Argon Discharges
Names of Authors: A. M. El-Chemali¹, J. L. Manceau²
Authors’ Affiliations: ¹Department of Physics, Faculty of Science, Lebanese University, Beirut, Lebanon; ²Laboratoire Kastler Brossel, Sorbonne Université, CNRS, Paris, France
Abstract: Noble gas mixtures are widely utilized in plasma processing reactors, gas lasers, and radiation detection instrumentation. This study develops a self-consistent kinetic simulation model to analyze electron transport properties and compute excitation rates in low-pressure helium-argon (He-Ar) gas mixtures. We solved the electron Boltzmann equation using a multi-term spherical harmonic expansion scheme across a reduced electric field range (E/N) from 2.0 Td to 500.0 Td. The model incorporates comprehensive cross-section sets, including elastic scattering, electronic excitation, and direct impact ionization, while accounting for Penning ionization processes. Our modeling results show that adding small fractions of argon (from 1.0% to 5.0% by volume) drastically distorts the electron energy distribution function. At a field strength of E/N = 25.0 Td, the total ionization rate coefficient increases by over two orders of magnitude in the 95% He - 5% Ar mixture compared to pure helium. This enhancement is driven by Penning collisions between metastable helium atoms and ground-state argon atoms. The calculated electron drift velocities and longitudinal diffusion coefficients match independent swarm experimental measurements within a ±4.5% variance. These kinetic parameters provide essential baseline input data for optimizing industrial plasma processing chambers.
Keywords: Helium-argon mixtures; Boltzmann equation; electron transport; Penning ionization; cross-section; plasma modeling
Manuscript Timeline: Received: March 11, 2016; Revised: May 19, 2016; Accepted: June 11, 2016; Published: July 09, 2016
Citation: El-Chemali, A. M., & Manceau, J. L. (2016). Kinetic Simulation of Electron Transport and Excitation Rates in Low-Pressure Helium-Argon Discharges. International Journal of Physics, 7(7), 49–56.
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