Heat transport of nitrogen in helium atmospheric pressure microplasma

TL;DR

This study investigates how nitrogen's vibrational and rotational temperatures change in helium atmospheric microplasma, revealing energy transfer priorities and temperature variations with different gas fluxes and currents.

Contribution

It provides new insights into nitrogen's heat transport mechanisms and energy transfer dynamics in helium microplasma at atmospheric pressure.

Findings

Vibrational temperature of nitrogen increases from 3200 to 4622 K.

Rotational temperature of nitrogen decreases from 1270 to 570 K.

Vibrational energy gain exceeds rotational energy in nonequilibrium conditions.

Abstract

Stable DC atmospheric pressure normal glow discharges in ambient air were produced between the water surface and the metallic capillary coupled with influx of helium gas. Multiple independent repeated trials indicated that vibrational temperature of nitrogen rises from 3200 to 4622 K, and rotational temperature of nitrogen decreases from 1270 to 570 K as gas flux increasing from 20 to 80 sccm and discharge current decreasing from 11 to 3 mA. Furthermore, it was found that the vibrational degree of the nitrogen molecule has priority to gain energy than the rotational degree of nitrogen molecule in nonequilibrium helium microplasma.