Modelagem de espectros de emissão óptica: o caso do segundo sistema positivo do N2

Abstract

The present work introduces a methodology to address simulations of rotational spectra induced by low-temperature electrical discharges. To achieve this, a kinetic cycle is employed, continuously integrating the temporal evolution of molecular, ionic, and atomic nitrogen species within the zero-dimensional plasmachemical solver (ZDPlasKin). Given that the analysis of emission spectra is a commonly used diagnostic tool for electrical discharges in gases, transitions between the rovibrational levels of the second positive system N2(C 3Πu, v′ = 0, J′ → B3Πg, v ′′ = 0, J′′) of molecular nitrogen are chosen as the case study. This approach provides real-time insights into the gas behavior during the discharge. To determine the intensities of each optical transition of the second positive system, two distinct approaches are presented. The first method uses absolute densities of emitting species, while the second involves an analysis of reaction pathways. Remarkably, both methods yield highly comparable results when inserted into the model used. Additionally, synthetic spectra are qualitatively compared to experimental measurements conducted in a discharge tube. It is important to note that, within the proposed methodologies, the temporal evolution of spectra can be systematically evaluated.