Technical characteristics of a DC plasma jet with Ar/N2 and O2/N2 gaseous mixtures

Abstract

In this paper, the optical emission spectroscopy technique is used to examine the physical properties and technical characteristics of the plasma discharge in a fabricated DC plasma jet. The background gas is nitrogen molecular gas which is mixed with argon and oxygen gases at various percentages. The emission spectra are analyzed and, the plasma density, rotational, vibrational and excitation temperatures are obtained for the formed plasma discharges with Ar/N2 and O2/N2 mixtures. Moreover, the NO and OH lines from NOγ(A2Σ+→X2Πr), (A2Σ,v=0→X2Π,v′=0) excitation transitions are observed. It is shown that, at the higher argon and oxygen percentages in both the Ar/N2 and O2/N2 gaseous mixture, the emission intensities of argon ions and oxygen atoms are increased. In addition, at the higher Ar and O2 contributions in both the gaseous mixtures, while the rotational, vibrational and excitation temperatures are higher, they are decreased at the O2/N2 gaseous mixture. Moreover, the plasma electron density reduces for O2/N2 and increases for Ar/N2 gaseous mixture. On the other hand, for both the mixtures, the plasma density, rotational, vibrational and excitation temperatures are increased at the higher DC power source currents. Furthermore, it is seen that the N2 dissociation rate increases at the higher DC currents and Ar and O2 percentages in both the mixtures. However, N2 dissociation rate in the formed plasma jet with Ar/N2 gaseous mixture is higher.