Properties of Argon–Nitrogen Atmospheric Pressure DC Arc Plasma

Abstract

The effect of nitrogen addition (1-20 %) on atmospheric argon DC arc plasma parameters was investigated. Nitrogen was added to three initial plasma gas compositions: pure argon gas, argon gas with water aerosol, and argon gas with water aerosol containing 0.5 % KCl. Admixtures of nitrogen from 1 up to 10 % (in the case of Ar-N 2 -water aerosol plasma) or up to 5 % (in the presence of 0.5 % KCl) produced a more contracted discharge, with larger gradients of electron number density and temperature, as compared to plasma without molecular gas addition. The opposite effect was observed in gas mixtures with 20 % of nitrogen. In that case, the arc core was expanded, and the radial profile of electron density and temperature became flatter as compared to the case of pure argon plasma. The changes in the radial structure of the discharge could be explained by increased thermal conductivity of mixed gas plasma and the presence of molecular ions. Increasing nitrogen content brings plasma closer to thermal equilibrium. To evaluate the effect of nitrogen upon analytic performance of the arc source, limits of detection (LODs) were measured for Zn, Cu, Li, and Rb. In plasma without KCl, the addition of nitrogen resulted in lowering of LODs for Cu, Li and Rb, while the opposite was observed for Zn. In the presence of KCl the addition of nitrogen had little or no effect on LODs for Cu, Li and Rb, while detection limits for Zn were increased.

Fabrication of Graphene Sheets Using an Atmospheric Pressure Thermal Plasma Jet System

“…We found that the I G /I 2D ratio for samples A and B were 3.53 and 3.04, respectively, which corresponded to the multilayer graphene [44,45]. The addition of N 2 gas with Ar improved the thermal conductivity of the mixed plasma and increased the number of molecular ions [46]. The improved thermal and electrical conductivity of the nitrogen provided better nucleation conditions and, hence, more graphene layers were obtained.…”

Optical Investigations of N2 Atmospheric Pressure Plasma Jets

“…Observation of N2 + (B 2 ∑u + →X 2 ∑g + ) transitions also indicates that N2 + is abundant [10]. Characteristic emissions and numerical calculations of species such as N2, N2 + , N + , and N in low-and atmospheric pressure of nitrogen luminescent (glow) discharges have been examined [11,12]. N2 and N2 + species in nitrogen plasma play vital role in synthesis of new functional and mechanical materials as they have strong chemical activity.…”

Numerical simulation and analysis of lithium plasma during low-pressure DC arc discharge

“…Most of the research on low-pressure arc discharge fields concentrate on the gas discharge [7][8][9][10][11][12][13], the theoretical and experimental research on the gaseous form of alkali metal DC arc discharge are less reported. In this paper, the numerical and simulation modeling of lithium-vapor DC arc discharge in a low-pressure environment is studied.…”