Predicting Streamer Discharge Front Splitting by Ionization Seed Profiling

TL;DR

This study introduces a 2D deterministic model linking ionization seed profiles to streamer front splitting, aiding in predicting and controlling streamer discharge branching.

Contribution

It develops an indicative profiles approach that correlates seed profile irregularities with streamer branching, advancing predictive capabilities.

Findings

Seed profile irregularity correlates with streamer front splitting.

Voltage, seed size, and preionization influence branching behavior.

Model provides a basis for experimental prediction of streamer branching.

Abstract

Previous studies of streamer discharge branching mechanisms have mainly been generative other than predictive. To predict or even control branching, a reliable connection between experimental conditions and streamer branching needs to be established. As an important step toward the goal, in this work, a 2D deterministic model of negative streamers in air is numerically solved with the ionization seeds assumed as the superposition of Gaussians. The "indicative profiles approach" developed here can consistently relate the change in a quantitative measure of geometrical irregularity of the seed profiles with specific electron densities to the emergence of front splitting of streamer discharges under various voltages, seed characteristic sizes, and preionization levels. The results of this study could inform experiments to identify and clarify streamer branching mechanisms.