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

Cold atmospheric pressure plasmas (CAPP) have been widely tested for numerous applications showing promising results and an increasing interest due to the low running cost and operational simplicity. However, there is a lack of understanding about the main mechanisms involved in the plasma dynamics. In this work, we show that the ion species are often strongly coupled in CAPP and this leads to physical effects that currently are not accounted for in standard simulation techniques. Using first-principles Molecular Dynamics simulations, we observed that the ion and neutral temperatures are influenced by Disorder Induced Heating (DIH), ion-neutral temperature relaxation through collisions and ion-neutral 3-body recombination. The observed effects show that CAPP are sufficiently dense that they are influenced by strong correlation effects associated with many-body interactions that are not treated in the dilute limit.