Simulation and modeling of a non-neutral discharge regime of atmospheric pressure plasma jets

In contrast to low-pressure plasmas, where the Debye length λ_D and the discharge length L differ by several orders of magnitude, many atmospheric pressure plasmas inherit comparable scales for these quantities. As a result of this characteristic, atmospheric pressure plasmas can fail to develop a quasi-neutral bulk region and operate within a non-neutral discharge regime. We observe and analyze this operation regime by applying a one-dimensional hybrid particle-in-cell/Monte Carlo collisions (PIC/MCC) simulation for the cross-section of the jet. The results indicate that the electrons become organized within a soliton-like Gaussian-shaped structure. Their dynamics are dominated by the dynamics of this soliton structure, for which a naive analytical model was developed. Furthermore, a direct comparison between the analytical model and the simulation results is achieved that validates the conclusions drawn from the analysis of the model. The main goal of our work is to analyze the electron dynamics of the aforementioned non-neutral discharge regime of capacitively coupled atmospheric pressure plasma jets.