Spectroscopic of atmospheric pressure air jet plasma in transverses arc discharge

TL;DR

This study spectroscopically characterizes atmospheric pressure air jet plasma in a transverse arc discharge, identifying emission lines and determining excitation temperatures, revealing non-local thermodynamic equilibrium conditions.

Contribution

It provides detailed spectroscopic analysis and temperature measurements of air plasma in transverse arc discharge, highlighting non-LTE effects and plasma composition.

Findings

Identified atomic and molecular emission lines in the plasma.

Determined excitation temperatures of atoms and molecules.

Found non-LTE conditions in the plasma during evolution.

Abstract

Spectroscopic characterization of a specific case of the atmospheric pressure air jet plasma in the transverse cw dc arc discharge of high voltage was done. Within the spectrum of wavelengths from 200 to 1100 nm all remarkable emissions were monitored, and all excited atomic lines of N, O, H and molecular bands of NO, N2, O2, OH, CO, CN were identified. Using relative intensities of analytical CuI lines 510.5, 515.3, 521.8 nm (the product of electrode emission) and N2 2+ -system band at 337.1 nm (the dominating component of plasma-forming gas), the temperature of electronic excitation of free atoms, Texc, and the temperatures of excitation of vibrational and rotational states of molecules, TV and TR, were determined. It was found that there is no local LTE in this arc discharge air plasma during its space/time evolution, and effects of strong non-izothermality have a place in this case.