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arXiv · 2207.11351

Strong Coulomb Coupling Influences Ion and Neutral Temperatures in Atmospheric Pressure Plasmas

M. D. Acciarri·C. Moore·S. D. Baalrud
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Abstract

Molecular dynamics simulations are used to model ion and neutral temperature evolution in partially-ionized atmospheric pressure plasma at different ionization fractions. Results show that ion-ion interactions are strongly coupled at ionization fractions as low as 10^-5 and that the temperature evolution is influenced by effects associated with the strong coupling. Specifically, disorder-induced heating is found to rapidly heat ions on a timescale of the ion plasma period (~10s ps) after an ionization pulse. This is followed by the collisional relaxation of ions and neutrals, which cools ions and heats neutrals on a longer (~ns) timescale. Slight heating then occurs over a much longer (~ 100s ns) timescale due to ion-neutral three-body recombination. An analytic model of the temperature evolution is developed that agrees with the simulation results. A conclusion is that strong coupling effects are important in atmospheric pressure plasmas.

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M. D. Acciarri, C. Moore, S. D. Baalrud. 2022-07-22. Strong Coulomb Coupling Influences Ion and Neutral Temperatures in Atmospheric Pressure Plasmas. https://doi.org/10.1088/1361-6595%2Faca69c

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