Vibrational Relaxation of Carbon Dioxide in Argon

Kamimoto, Goro; Matsui, Hiroyuki

doi:10.1063/1.1673870

Cited by 11 publications

(3 citation statements)

References 7 publications

(7 reference statements)

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“…12 . Good agreement is seen with the data measured by Kamimoto et al [ 38 ] who studied mixtures 4% CO - Ar with an emission technique. For dilute CO in argon, the Simpson model [ 32 ] was found to be largely within the uncertainty of the measurements.…”

Section: Results/sensor Demonstrationsupporting

confidence: 88%

“…From the tests performed in this work, thermal non-equilibrium was investigated and compared to rates of vibrational excitation predicted from the Park [ 9 ] and Simpson [ 32 ] models. Our results show good agreement with the Simpson model and the measurements of Kamimoto et al [ 38 ]. On a few tests cases at low shock velocity, a single vibrational temperature could not be determined at early test times.…”

Section: Discussionsupporting

confidence: 90%

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High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

2022

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A high-speed laser absorption technique is employed to resolve spectral transitions of CO$$_2$$ 2 in the mid-infrared at MHz rates to infer non-equilibrium populations/temperatures of translation, rotation and vibration in shock-heated CO$$_2$$ 2 - Ar mixtures. An interband cascade laser (DFB-ICL) resolves 4 transitions within the CO$$_2$$ 2 asymmetric stretch fundamental bands ($$\Delta $$ Δ v$$_3$$ 3 = 1) near 4.19 $$\upmu \hbox {m}$$ μ m . The sensor probes a wide range of rotational energies as well as two vibrational states (00$$^0$$ 0 0 and 01$$^1$$ 1 0). The sensor is demonstrated on the UCLA high enthalpy shock tube, targeting temperatures between 1250 and 3100 K and sub-atmospheric pressures (up to 0.2 atm). The sensor is sensitive to multiple temperatures over a wide range of conditions relevant to Mars entry radiation. Vibrational relaxation times are resolved and compared to existing models of thermal non-equilibrium. Select conditions highlight the shortcomings of modeling CO$$_2$$ 2 non-equilibrium with a single vibrational temperature.

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Section: Results/sensor Demonstrationsupporting

confidence: 88%

Section: Discussionsupporting

confidence: 90%

High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

2022

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“…Using this terminology, observation (ii) means that IVR is fast (enhanced by strong Fermi-resonance 24,25 between the bend and symmetric stretch vibrations) compared to the overall VET time scale, and the rate limiting process is CET. Later studies [26][27][28][29][30][31] corroborated these findings.…”

Section: Introductionmentioning

confidence: 62%

Molecular dynamics modeling of cooling of vibrationally highly excited carbon dioxide produced in the photodissociation of organic peroxides in solution

Kandratsenka

Schroeder

Schwarzer

et al. 2005

Phys. Chem. Chem. Phys.

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Non-equilibrium (NEMD) and equilibrium (EMD) molecular dynamics simulations are performed to investigate the vibrational cooling and asymmetric stretch spectral evolution of highly excited carbon dioxide produced in the photodissociation of organic peroxides in the solvents dichloromethane, carbon tetrachloride and xenon. Due to strong Fermi resonance the symmetric stretching and bending modes of carbon dioxide in CH2Cl2 and CCl4 jointly relax on a ten and hundred picosecond timescale, respectively, which is in accordance with experiment. However, the high frequency CO2 asymmetric stretch vibration relaxes on a considerably longer time scale because of weak interaction with the other modes. The relaxation rate coefficients of (and works done by) different modes obtained from NEMD and the Landau-Teller rate coefficients calculated through equilibrium force time correlation functions are in reasonable agreement. The analysis of these results leads to the conclusion that, in contrast to xenon where the relaxation takes about 20 ns, the shorter time scales in CH2Cl2 and CCl4 are caused by efficient near resonant vibration to vibration energy transfer from carbon dioxide to solvent molecules. The results of the non-equilibrium simulations are used to monitor the quasi-stationary asymmetric stretch infrared spectra of carbon dioxide during the cooling process. Comparison of the corresponding experimental results suggests that carbon dioxide initially is produced with a broad distribution of energy disposed in its bend and symmetric stretch modes while the asymmetric stretch mode remains unexcited.

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Vibration–Vibration energy exchange between N₂O and CO

Suitor

Kuby

1975

Int J of Chemical Kinetics

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The temperature dependence of the vibration-vibration energy transfer between the mode of l5Nl4NO and the first vibrational level of CO was determined over a range of 680 to 1300°K using a shock tube. Several mixtures of 15NI4NO-CO were tested, diluted in 95% Ar.The resulting exothermic transfer probabilities for the reaction, 15N14N0(001) + CO(0) -+ 15N14N0(000) + CO (1) are compared to previous work on N,O-CO.The results for 15N14NO-C0 exhibit a more pronounced direct temperature dependence than for NZO-CO even though the process has a closer resonance (AE = 59 cm-1 for 15N14NO-C0 and AE = 81 cm-1 for NzO-CO). Past theoretical studies [ 1-71 supported by experimental investigations IS, 91show that the participation of long-range molecular force interactions results in a different temperature dependence for the transfer probabilities than predicted using short-range force interactions. Long-range forces such as dipole-dipole or dipole-quadrupole theoretically yield an inverse temperature dependence of the transfer probabilities as opposed to the direct temperature dependence predicted using short-range forces. In addition, the effect of long-range forces tends to be more pronounced as the nonresonance of the collison partners AE that for dipole-dipole interactions the inverse temperature dependence will not manifest itself until the energy defect is much smaller. To investigate this further a study of the vibration-vibration relaxation between the v3 mode of * Present address:

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Vibrational Relaxation of Carbon Dioxide in Argon

Cited by 11 publications

References 7 publications

High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

Molecular dynamics modeling of cooling of vibrationally highly excited carbon dioxide produced in the photodissociation of organic peroxides in solution

Vibration–Vibration energy exchange between N₂O and CO

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Vibrational Relaxation of Carbon Dioxide in Argon

Cited by 11 publications

References 7 publications

High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

High-speed mid-infrared laser absorption spectroscopy of CO$$_2$$ for shock-induced thermal non-equilibrium studies of planetary entry

Molecular dynamics modeling of cooling of vibrationally highly excited carbon dioxide produced in the photodissociation of organic peroxides in solution

Vibration–Vibration energy exchange between N2O and CO

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Vibration–Vibration energy exchange between N₂O and CO