Carbon Monoxide Formation in Co2 Lasers

Wiegand, W. J.; Fowler, Michael C.; Benda, J. A.

doi:10.1063/1.1653177

Cited by 47 publications

(10 citation statements)

References 6 publications

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“…Different authors use different cross sections to estimate the dissociation rate coefficient. The 7 eV excitation cross section from Phelps [75,187], as used by [203][204][205], seems to lead to a reasonable calculation of CO 2 dissociation in various conditions [88,202]. However, in a recent experimental study [89] Morillo-Candas et al have shown that electron impact dissociation of CO 2 is very well described in the range E/N ∈ (45, 105) Td by the cross sections calculated by Polak and Slovetsky [206], while the Phelps 7 eV cross section leads to an overestimation of the dissociation rate coefficient.…”

Section: Comentioning

confidence: 99%

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

et al. 2021

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Numerous applications have required the study of CO2 plasmas since the 1960s, from CO2 lasers to spacecraft heat shields. However, in recent years, intense research activities on the subject have restarted because of environmental problems associated with CO2 emissions. The present review provides a synthesis of the current state of knowledge on the physical chemistry of cold CO2 plasmas. In particular, the different modeling approaches implemented to address specific aspects of CO2 plasmas are presented. Throughout the paper, the importance of conducting joint experimental, theoretical and modeling studies to elucidate the complex couplings at play in CO2 plasmas is emphasized. Therefore, the experimental data that are likely to bring relevant constraints to the different modeling approaches are first reviewed. Second, the calculation of some key elementary processes obtained with semi-empirical, classical and quantum methods is presented. In order to describe the electron kinetics, the latest coherent sets of cross section satisfying the constraints of "electron swarm" analyses are introduced, and the need for self-consistent calculations for determining accurate electron energy distribution function (EEDF) is evidenced. The main findings of the latest zero-dimensional (0D) global models about the complex chemistry of CO2 and its dissociation products in different plasma discharges are then given, and full state-to-state (STS) models of only the vibrational-dissociation kinetics developed for studies of spacecraft shields are described. Finally, two important points for all applications using CO2 containing plasma are discussed: the role of surfaces in contact with the plasma, and the need for 2D/3D models to capture the main features of complex reactor geometries including effects induced by fluid dynamics on the plasma properties. In addition to bringing together the latest advances in the description of CO2 non-equilibrium plasmas, the results presented here also highlight the fundamental data that are still missing and the possible routes that still need to be investigated.

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Section: Comentioning

confidence: 99%

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

et al. 2021

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“…This linearity provides experimental evidence of the validity of the assumptions underlying the used method for the determination of the CO concentration. A detailed description of the method can be found in [2].…”

Section: Methodsmentioning

confidence: 99%

“…for lower E/N). Since the variations of the reduced electric field strength E/N with discharge current are very small, the changes in CO 2 dissociation are due to changes in the electron density and in the rate of the regeneration processes (reactions (2) and (3)). On the one hand, the electron density and hence the production of CO molecules by electron impact increases with discharge current.…”

Section: Steady-state Co 2 Decompositionmentioning

confidence: 99%

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Spectroscopic Study of CO2 Decomposition in Sealed-off CO2 Lasers

Kylián

Leys

Hrachová

2001

Contrib. Plasma Phys.

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“…It is well-known that CO 2 molecule dissociates in an electric discharge leading to the formation of CO and O 2 in the CO 2 laser gain medium and the extent of CO formation has been measured experimentally by many researchers in the past [14,15]. The discharge conditions, along with flow rate, gas composition etc, influence the dissociation.…”

Section: Introductionmentioning

confidence: 99%

Experimental estimation of CO concentration in LN₂ cooled CW CO laser operating with CO₂ laser gas mixture

Dwivedi¹,

Ghosh²,

Prasad³

et al. 2022

Laser Phys. Lett.

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The lasing medium of cryo-cooled CW-CO laser operated with CO2 laser gain medium (CO2–N2–He mixture) resulting in 5 µm emission is formed in-situ in the discharge and its composition, that is sensitively dependent on the discharge temperature, is not known a priori. The composition of the CO lasing gas mixture here was successfully arrived at by way of sampling the gas mixture at the exhaust and measuring the wavelength dependent absorbance by a Fourier Transform Infrared Spectrophotometer. This enabled us to determine the CO and CO2 concentrations in the lasing mixture accurately while the other major constituents were estimated from the initial partial pressures. The composition of the lasing gas mixture was studied for various discharge wall temperatures starting from no cooling condition (∼351 K) to LN2 cooled conditions (79 K). While the concentrations of both, CO2 and CO were found to decrease for temperatures below the freezing point of CO2 at the operating pressure of 11 mbar, the relative concentration of CO with respect to CO2 also increased with reducing temperature accompanied by a steady increase in the CO laser power output. The onset of lasing in 5 µm region was found to occur at a discharge wall temperature of 212 K.

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Carbon Monoxide Formation in Co2 Lasers

Cited by 47 publications

References 6 publications

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

Spectroscopic Study of CO2 Decomposition in Sealed-off CO2 Lasers

Experimental estimation of CO concentration in LN₂ cooled CW CO laser operating with CO₂ laser gas mixture

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Carbon Monoxide Formation in Co2 Lasers

Cited by 47 publications

References 6 publications

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

Advances in non-equilibrium $$\hbox {CO}_2$$ plasma kinetics: a theoretical and experimental review

Spectroscopic Study of CO2 Decomposition in Sealed-off CO2 Lasers

Experimental estimation of CO concentration in LN2 cooled CW CO laser operating with CO2 laser gas mixture

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Product

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Experimental estimation of CO concentration in LN₂ cooled CW CO laser operating with CO₂ laser gas mixture