Experimental study of a planar atmospheric-pressure plasma operating in the microplasma regime

TL;DR

This study investigates how reducing electrode gap in a nonthermal atmospheric-pressure microplasma affects electrical characteristics, revealing a distinct operational regime with increased current and power density at lower voltages.

Contribution

It provides experimental and theoretical insights into the behavior of microplasmas at submillimeter electrode gaps, highlighting a new operational regime.

Findings

Current and power density increase with decreasing electrode gap.

Sheath thickness and electric fields depend on electrode gap size.

A distinct plasma regime emerges at submillimeter gaps.

Abstract

Electrical characterization of a nonthermal radio-frequency atmospheric-pressure microplasma in a parallel plate configuration has shown that reducing electrode gap into the submillimeter range increases current and power density at a reduced voltage as compared to similar plasmas at larger electrode gaps which have no gap dependence. Calculation of sheath thickness and electric fields in the sheath and in the bulk demonstrate a dependence on the electrode gap as it is reduced into the submillimeter regime, indicating a distinct regime of operation.