Ionization wave propagation on a micro cavity plasma array

TL;DR

This paper investigates ionization wave propagation in microcavity plasma arrays, combining experimental observations and numerical simulations to understand the wave dynamics and underlying mechanisms at atmospheric pressure.

Contribution

It introduces a novel study of wave-like ionization propagation in microcavity plasma arrays, integrating experimental data with simulation insights.

Findings

Ionization wave propagates at about 5 km/s

Wave propagation driven by electron and ion drift and photoemission

Strong interaction observed between individual cavities

Abstract

Microcavity plasma arrays of inverse pyramidal cavities have been fabricated in p-Si wafers. Each cavity acts as a microscopic dielectric barrier discharge. Operated at atmospheric pressure in argon and excited with high voltage at about 10 kHz, each cavity develops a localized microplasma. Experiments have shown a strong interaction of individual cavities, leading to the propagation of wave-like optical emission structures along the surface of the array. This phenomenon is numerically investigated using computer simulation. The observed ionization wave propagates with a speed of about 5 km/s, which agrees well the experimental findings. It is found that the wave propagation is due to sequential contributions of a drift of electrons followed by drift of ions between cavities seeded by photoemission of electrons by the plasma in adjacent cavities.