Vibrational distributions in a flowing nitrogen glow discharge

Abstract

A spectroscopical investigation of a flowing DC nitrogen discharge is realized for determining the vibrational distributions of radiative excited states and . The distributions are found to be Boltzmannian and the characteristic vibrational temperatures increase with the discharge current but are not affected by the flow rate and pressure variations in the range 1 - 3 Torr. The vibrational distribution of the ground state is deduced from the distribution, following the Franck - Condon principle.

Time resolved optical emission spectroscopy in power modulated atmospheric pressure plasma jet

“…Moreover, the dissociation of molecules (and thus formation of very reactive atomic radicals) is often governed by step-wise vibrational excitation. The T vib of molecular nitrogen can be determined using the 2 nd positive system of a nitrogen emission spectrum [26]. This implies the electronic transition C 3 Π u → B 3 Π g .…”

“…As the nitrogen spectral bands (Fig. 2) were recorded with sufficient intensity and resolution, one may use [26] either the first negative system at 391.4 nm or second positive system bands at 337.4 or 380.4 nm. In this paper, it was chosen (Table 4) [41].…”

Formation and Excitation of CN Molecules in He–CO–N2–O2 Discharge Plasmas

“…The relation between the N 2 vibrational temperatures in the ground and excited states has been investigated and discussed by many authors, see e.g. [57][58][59][60][61][62][63][64]. These temperatures may differ significantly and their relation is rather complicated when there are more excitation channels, including the process: N 2 ðAÞ þ N 2 ðAÞ !…”

Wall material interaction with the active species in a nitrogen–methane D.C. flowing discharge

“…As a result, the addition of hydrogen in nitrogen discharge containing oxygen gives rise to the appearance of dissociation processes of nitrogen and oxygen molecules which leads to the formation of chemical species such as NO, OH, NH and water vapours, avoiding formation of metal oxides. In our previous papers [11,12], notable changes in the active species population were reported to appear in nitrogen D.C. flow discharges on addition of small amounts of hydrogen/methane. For instance, increases of the N 2 (C) population as high as 6 times were recorded for (N 2 exH 2 ) gas mixtures, with "x" ranging between (0.1e0.5)% [13].…”