Characterization of transient discharges under atmospheric pressure conditions applying nitrogen photoemission and current measurements

TL;DR

This study combines numerical simulation, optical emission spectroscopy, and current measurements to characterize plasma parameters of various atmospheric-pressure transient discharges, improving accuracy through complementary methods.

Contribution

It introduces a combined diagnostic approach using nitrogen emissions and current measurements to accurately determine plasma parameters of transient discharges.

Findings

Current measurements help resolve ambiguities in plasma parameter determination.

Nitrogen emissions serve as effective sensors when admixed with argon.

The combined methods improve the accuracy of plasma characterization.

Abstract

The plasma parameters such as electron distribution function and electron density of three atmospheric-pressure transient discharges namely filamentary and homogeneous dielectric barrier discharges in air, and the spark discharge of argon plasma coagulation (APC) system are determined. A combination of numerical simulation as well as diagnostic methods including current measurement and optical emission spectroscopy (OES) based on nitrogen emissions is used. The applied methods supplement each other and resolve problems, which arise when these methods are used individually. Nitrogen is used as sensor gas and is admixed in low amount to argon for characterizing the APC discharge. Both direct and stepwise electron impact excitation of nitrogen emissions are included in the plasma-chemical model applied for characterization of these transient discharges using OES where ambiguity arises in the determination of plasma parameters at specific discharge conditions. It is shown that the measured current solves this problem by providing additional information useful for the determination of discharge-specific plasma parameters.