Modeling Streamer Physics in 2D and 3D Wedge Pin-to-Plane Geometries via a PIC-DSMC Code

Streamer propagation physics is investigated in 2D and 3D pin-to-plane geometries via a PIC-DSMC code with an air model$^{\mathrm{1}}$ using Townsend breakdown and streamer mechanisms via tracking excited state neutrals that can either undergo quenching or spontaneous photon emission collisions$^{\mathrm{2}}$. A 100 $\mu $m radius 1 eV-10$^{\mathrm{18}}_{\mathrm{\thinspace }}$m$^{\mathrm{-3}}$ plasma placed at the tip of a 100 $\mu $m hemispherical pin electrode (at 6 kV) in a 600 Torr air filled gap, 1.5 mm above a planar grounded cathode, seeds the domain. Prior 2D studies have shown that E/n can significantly impact streamer evolution$^{\mathrm{3}}_{\mathrm{.}}$ We extend the analysis to 3D wedge geometries (to limit computational costs) with wedge angle swept from 10$^{\mathrm{o}}$ to 45$^{\mathrm{o}}$ to examine its effect on streamer branching, propagation, and particle noise. 1. C.Moore \textit{et al}., \textit{Development of PIC-DSMC Air Breakdown Model in the Presence of a Dielectric}, ICOPS, 2016. 2. A.Fierro \textit{et al}., \textit{Discrete Photon Implementation for Plasma Simulations}, Physics of Plasma, 23, 2016. 3. A.Jindal \textit{et al}., \textit{Streamer Formation Near a Dielectric Surface with Variable Quantum Efficiency}, ICOPS, 2017.