Optical emission spectroscopy of atmospheric-pressure non-equilibrium plasma with mist injection

Masanao Tsumaki,Tsuyohito Ito

doi:10.1063/1.5011076

Abstract

This paper describes optical emission spectroscopic diagnostics of atmospheric-pressure non-equilibrium plasma with mist injection. Electron number densities and gas temperatures are estimated from Hβ (486 nm) and OH (309 nm) spectra to be on the order of 1015 cm-3 and 440–540 K, respectively, for the conditions tested in this study. Comparison of the rotational temperatures of N2 and OH indicates that two-temperature analysis of OH rotational spectra provides gas temperature even with mist injection.

Highlights

INTRODUCTIONConcentration of a few thousand parts per million (ppm), we remain unaware of whether such analysis is applicable to analyses in more humid conditions such as those occurring with mist injection (approx. 60,000 ppm in this study), or not
Plasma-induced chemical reactions in liquids have been studied extensively and used widely for biomedical and materials processing applications.[1,2,3,4,5] Researchers are often attracted by highly reactive radicals such as H and OH generated by plasma because such radicals can greatly improve processing by enhancing chemical reactions in and on liquids
For this study, we perform optical emission spectroscopy to estimate the electron number density and gas temperature of atmospheric-pressure non-equilibrium He plasma with mist injection, via Stark broadening of Hβ line and rotational temperature of OH

Summary

INTRODUCTION

Concentration of a few thousand parts per million (ppm), we remain unaware of whether such analysis is applicable to analyses in more humid conditions such as those occurring with mist injection (approx. 60,000 ppm in this study), or not. Concentration of a few thousand parts per million (ppm), we remain unaware of whether such analysis is applicable to analyses in more humid conditions such as those occurring with mist injection 60,000 ppm in this study), or not. As described in this paper, validation of two-temperature analysis of OH rotational temperature is provided by a comparison with N2 rotational temperature, the latter of which is a good indicator of the gas temperature.[13]

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSION