Strong Correlation Effects in Molecular Atmospheric Pressure Plasmas

Atmospheric pressure plasmas have shown great promise in reducing the cost, complexity, and carbon footprint of existing technologies across a number of industries. Traditional modeling of these plasmas assumes weak ion-ion coupling despite the existence of strong coupling at ionization fractions as low as 10^-5. Recent work on atomic plasma has shown that strong correlation effects can drastically increase the ion temperature through Disorder Induced Heating (DIH) and subsequently increase the neutral temperature through ion-neutral collisional relaxation [1]. We extend this work to molecular plasmas and show that the added rotational degrees of freedom also gain energy from DIH, leading to an equilibrium temperature below what is predicted for atomic plasmas. We also extend the work to higher pressures and show that increased pressure leads to higher equilibrium temperature and faster relaxation. We derive a new model for the equilibrium temperature and confirm its accuracy using Molecular Dynamics (MD) simulations. We also model the relaxation of translational and rotational temperatures of the ion and neutral species in the molecular system.