Metastable atomic species in the N2 flowing afterglow

Levaton, J.; Amorim, J.

doi:10.1016/j.chemphys.2011.11.010

Cited by 24 publications

(21 citation statements)

References 36 publications

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“…, p is the gas pressure in Torr) [9]. This procedure to obtain the electron density was utilized in several of our works on nitrogen discharges and post-discharges [8,[10][11][12][13][14][15][16][17][18]. We utilized high purity N 2 gas (99.999%) in this study.…”

Section: Experimental Setup and Resultsmentioning

confidence: 99%

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

2020

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We investigated flowing N 2 DC discharges both experimentally and theoretically. The discharge gas and N 2 (X 1 Σ + g) vibrational temperatures, electron density (n e), reduced electric field (E/N), and radiative state densities were measured by optical emission spectrometry (OES) and Langmuir double probes. We formulated a discharge kinetic numerical model to calculate the densities of nitrogen species as functions of the gas residence time. We combine the experimental parameters measured in the discharge with the kinetic model to analyze different discharge conditions where E/N varies significantly. First, we analyzed the measured and calculated radiative states densities and N 2 (X 1 Σ + g) vibrational distributions at the end of the positive column. Results show good agreement between calculated and measured parameters. Then, we studied the excited molecular species densities, and neutral and excited atoms densities as functions of the discharge gas residence time. This work presents for the first time the temporal densities of excited molecular and atomic states from 10 −9 to 10 −1 s discharge residence times, calculated for experimental conditions where n e presents a low variation and E/N varies from high (94 Td) to relatively low values (48 Td). The discharge experimental conditions are discharge current of 60 mA, gas pressure of 230-530 Pa, and gas flow rate of 0.9 Slm −1. Keywords Neutral and excited atoms density. Neutral and excited molecule density. Nitrogen flowing discharges

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Section: Experimental Setup and Resultsmentioning

confidence: 99%

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

2020

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“…In the observed afterglow region, collisional processes in the pink afterglow [15] also excite the N 2 (B) states, in addition to reaction (b).…”

Section: No Titrationmentioning

confidence: 92%

“…In Fig. 2a for pure N 2 plasma, the N + 2 391.4 nm band is intense, characterizing the pink afterglow which is dominated by reactions between vibrationally excited N 2 (X,v) molecules and between N 2 (A,a') metastable molecules [14,15]. In Fig.…”

Section: No Titrationmentioning

confidence: 94%

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Determination of N and O‐atoms and N₂ (A) Metastable Molecule Densities in the Afterglows of N₂‐H₂, Ar‐N₂‐H₂ and Ar‐N₂‐O₂ Microwave Discharges

Zerrouki

Ricard

Sarrette

2014

Contrib. Plasma Phys.

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Key words Optical emission spectroscopy, microwave flowing afterglows, N2-H2, Ar-N2-H2, Ar-N2-O2 gas mixtures, N density, O density, N2 (A) density.Early afterglows of N 2-H2, Ar-N2-H2 and Ar-N2-O2 flowing microwave discharges are characterized by optical emission spectroscopy. The N and O atoms and the N2(A) metastable molecule densities are determined by optical emission spectroscopy after calibration by NO titration for N and O-atoms and measurements of NO and N2 band intensities. If an uncertainty of 30% is estimated on N-atomic density, an inaccuracy of one order of magnitude is obtained on the O and N2 (A) densities. In N2-(0.05-2.5%)H2 and Ar-(1-50%)N2-(0.05-2.5%) H2 gas mixtures, the O-atoms are coming from O2 impurities in the discharge. Concentrations of N and O-atoms and of N2 (A) densities are compared to the ones obtained in Ar-(5-50%)N2-(0.2-2.5%) O2 gas mixtures in which a controlled amount of O2 is added.

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“…Other collisional processes in the pink afterglow [7] also excite the N 2 (B) states, in addition to reaction R1. For this other part (1 − a N+N ), it is considered the reactions R4 and R5 whose rate coefficients are reported in [4]- [6].…”

Section: Density Of N2(x V > 13) Moleculesmentioning

confidence: 99%

Determination of N and O-Atoms, of N2(A) and N2(X, v > 13) Metastable Molecules and N2+ Ion Densities in the Afterglows of Ar-N2 Microwave Discharges

Ricard¹,

Zerrouki²,

Sarrette³

2015

JASMI

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Early afterglows of Ar-N2 flowing microwave discharges are characterized by optical emission spectroscopy. The N and O atoms, the N2(A) and N2(X, v > 13) metastable molecules and 2 N + ion densities are determined by optical emission spectroscopy after calibration by NO titration for N and O-atoms and measurements of NO and N2 band intensities. For an Ar-xN2 gas mixture with × increasing from 2 to 100% at 4 Torr, 100 Watt and an afterglow time of 3 × 10 −3 s at the 5 liter reactor inlet, it is found densities in the ranges of (2-6) × 10 14 cm −3 for N-atoms, one order of magnitude lower for N2(X, v > 13) and for O-atoms (coming from air impurity), of 10 10-10 11 cm −3 for N2(A) and of 10 8-10 9 cm −3 for 2 N + .

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Metastable atomic species in the N2 flowing afterglow

Cited by 24 publications

References 36 publications

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

Determination of N and O‐atoms and N₂ (A) Metastable Molecule Densities in the Afterglows of N₂‐H₂, Ar‐N₂‐H₂ and Ar‐N₂‐O₂ Microwave Discharges

Determination of N and O-Atoms, of N<sub>2</sub>(A) and N<sub>2</sub>(X, v > 13) Metastable Molecules and N<sub>2</sub><sup style="margin-left:-6px;">+</sup> Ion Densities in the Afterglows of Ar-N<sub>2</sub> Microwave Discharges

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Metastable atomic species in the N2 flowing afterglow

Cited by 24 publications

References 36 publications

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

Neutral and Excited Molecules and Atoms Densities in the Positive Column of Flowing N2 DC Discharges

Determination of N and O‐atoms and N2 (A) Metastable Molecule Densities in the Afterglows of N2‐H2, Ar‐N2‐H2 and Ar‐N2‐O2 Microwave Discharges

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Determination of N and O‐atoms and N₂ (A) Metastable Molecule Densities in the Afterglows of N₂‐H₂, Ar‐N₂‐H₂ and Ar‐N₂‐O₂ Microwave Discharges