Interaction of streamers in air and other oxygen-nitrogen mixtures

TL;DR

This paper investigates how streamers in air and similar gases interact, revealing electrostatic and photo-ionization effects, and proposes an indirect measurement method for photo-ionization based on these interactions.

Contribution

It introduces an efficient 3D simulation method for streamers and analyzes the competing electrostatic and photo-ionization interactions in different gas mixtures.

Findings

Electrostatic repulsion and attraction via photo-ionization influence streamer interactions.

Pressure and gas composition significantly affect interaction dynamics.

Proposes an indirect experimental approach to measure photo-ionization effects.

Abstract

The interaction of streamers in nitrogen-oxygen mixtures such as air is studied. First, an efficient method for fully three-dimensional streamer simulations in multiprocessor machines is introduced. With its help, we find two competing mechanisms how two adjacent streamers can interact: through electrostatic repulsion and through attraction due to nonlocal photo-ionization. The non-intuitive effects of pressure and of the nitrogen-oxygen ratio are discussed. As photo-ionization is experimentally difficult to access, we finally suggest to measure it indirectly through streamer interactions.