Rotational relaxation of CO by collisions with H 2 molecules: A comparison between theory and experiment

Bréchignac, Ph.; Picard‐Bersellini, A.; Charneau, R.; Launay, Jean–Michel

doi:10.1016/0301-0104(80)87065-0

Cited by 83 publications

(13 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The

K_{J, M \to J^{'}, M^{'}}

are the rates of population transfers from states | J M 〉 to states | J ′ M ′ 〉, and

γ_{JM, J^{'} M}^{PD}

are the rates of pure dephasing of the | J M 〉〈 J ′ M | coherences. The ECS expression of the former, derived from Hartmann and Boulet by introducing adiabaticity corrections into the infinite order sudden equations, is

\begin{matrix} K_{J, M \to J^{'} \leq J, M^{'}} & = (2 J + 1) (2 J^{'} + 1) \times \sum_{L \neq 0} {(\begin{matrix} J & J^{'} & L \\ M & - M^{'} & M^{'} - M \end{matrix})}^{2} \\ \times {(\begin{matrix} J & J^{'} & L \\ 0 & 0 & 0 \end{matrix})}^{2} \times \frac{Ω (J)}{Ω (L)} (2 L + 1) K_{L \to 0} \end{matrix}

which is used for downward transitions, the upward ones being deduced from detailed balance. Similarly, starting from Strekalov and Dickinson the dephasing contribution is

\begin{matrix} γ_{JM, J^{'} M}^{PD} & = \frac{1}{2} \sum_{L} () \end{matrix}

…”

Section: Theorymentioning

confidence: 99%

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar

Chaussard

Vieillard

Billard

et al. 2015

J Raman Spectroscopy

View full text Add to dashboard Cite

In this paper, laser-induced field-free alignment of CO 2 in mixtures with Ar is investigated under dissipative conditions (up to 15 bars) at room temperature. The degree of alignment is temporally monitored by a polarization spectroscopy technique, where a weak probe pulse measures the transient birefringence resulting from the alignment. The data are analyzed with a quantum mechanical density matrix formalism using properly J-dependent and M-dependent state-to-state transfer rates, which was previously successfully tested on pure CO 2 and CO 2 -He mixtures. The same consistency is obtained between experiments and calculations, in particular the decay times of both the transient revivals and the permanent component of the alignment are accurately predicted by the model.

show abstract

“…The

K_{J, M \to J^{'}, M^{'}}

are the rates of population transfers from states | J M 〉 to states | J ′ M ′ 〉, and

γ_{JM, J^{'} M}^{PD}

\begin{matrix} K_{J, M \to J^{'} \leq J, M^{'}} & = (2 J + 1) (2 J^{'} + 1) \times \sum_{L \neq 0} {(\begin{matrix} J & J^{'} & L \\ M & - M^{'} & M^{'} - M \end{matrix})}^{2} \\ \times {(\begin{matrix} J & J^{'} & L \\ 0 & 0 & 0 \end{matrix})}^{2} \times \frac{Ω (J)}{Ω (L)} (2 L + 1) K_{L \to 0} \end{matrix}

which is used for downward transitions, the upward ones being deduced from detailed balance. Similarly, starting from Strekalov and Dickinson the dephasing contribution is

\begin{matrix} γ_{JM, J^{'} M}^{PD} & = \frac{1}{2} \sum_{L} () \end{matrix}

…”

Section: Theorymentioning

confidence: 99%

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar

Chaussard

Vieillard

Billard

et al. 2015

J Raman Spectroscopy

View full text Add to dashboard Cite

show abstract

“…Some information on the absolute cross sections is available from the state-to-state measurements of Bréchignac et al 5 They measured relaxation rates of specific rotational states of CO(vϭ1) in an H 2 bath at 77 and 293 K with a time resolved IR-IR double resonance experiment. They extracted both thermally averaged total inelastic cross sections out of rotational states j ϭ9 and 10, and a few kinetic parameters that characterized a large matrix of state-to-state rate coefficients.…”

Section: Thermally Averaged Total Inelastic Cross Sectionsmentioning

confidence: 99%

“…To help determine whether the Jankowski and Szalewicz potential surface predicts the correct absolute magnitudes of cross sections, we have evaluated the total inelastic crosssection out of j CO ϭ10 for comparison with the 293 K result of Bréchignac et al 5 We performed a Boltzmann average over kinetic energies, using trapezoidal rule quadrature at energies below 200 cm Ϫ1 and Gauss-Laguerre quadrature at higher energies. The calculations for this average included only the rotationless level of H 2 in the basis set; they used the CS approximation above 100 cm Ϫ1 but full CC calculations at lower energy.…”

Section: Thermally Averaged Total Inelastic Cross Sectionsmentioning

confidence: 99%

See 1 more Smart Citation

State-to-state rotational excitation of CO by H2 near 1000 cm−1 collision energy

Antonova

Tsakotellis

Lin

et al. 2000

The Journal of Chemical Physics

View full text Add to dashboard Cite

Relative state-to-state rotationally inelastic cross sections for excitation of carbon monoxide by hydrogen were measured in a crossed molecular beam experiment at collision energies 795, 860, and 991 cm Ϫ1 . The results are compared to predictions of a recent ab initio potential energy surface ͓J. Chem. Phys. 108, 3554 ͑1998͔͒. The agreement is very good. A comparison with older data on thermally averaged total depopulation cross sections ͓Chem. Phys. 53, 165 ͑1980͔͒ indicates that the absolute magnitudes of the cross sections predicted by the surface are too high. The CO excitation is dominated by collisions that are elastic in H 2 rotation, and the collision dynamics are very similar for different rotational levels of hydrogen.

show abstract

“…This factor will increase the rates for H2 excitation by about 50% from the values for He. Experimental evidence in support of this procedure can be found in available pressure broadening data (Nerf and Sonnenberg 1975; ssr also Brechignac et al 1980).…”

Section: Exact Calculation Of Populationsmentioning

confidence: 78%

Far-infrared rotational emission by carbon monoxide

McKee¹,

Storey²,

Watson³

et al. 1982

ApJ

View full text Add to dashboard Cite

Accurate theoretical collisional excitation rates are used to determine the emissivities of CO rotational lines for 10 4 cm-3 < n(H2), 100 K < T < 2000 K, and J < 50. An approximate analytic expression for the emissivities which is valid over most of this region is obtained. Population inversions in the lower rotational levels occur for densities n(H2) -10 3-5 cm-3 and temperatures T > 50 K. Interstellar shocks observed edge-on are a potential source of millimeter-wave CO maser emission. The CC rotational cooling function suggested by Hollenbach and McKee (1919) is verified, and accurate numerical values given.Application of these results to other linear molecules should be straightforward.

show abstract

Rotational relaxation of CO by collisions with H 2 molecules: A comparison between theory and experiment

Cited by 83 publications

References 47 publications

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar

State-to-state rotational excitation of CO by H2 near 1000 cm−1 collision energy

Far-infrared rotational emission by carbon monoxide

Contact Info

Product

Resources

About

Rotational relaxation of CO by collisions with H 2 molecules: A comparison between theory and experiment

Cited by 83 publications

References 47 publications

Dissipation of post‐pulse laser‐induced alignment of CO2 through collisions with Ar

Dissipation of post‐pulse laser‐induced alignment of CO2 through collisions with Ar

State-to-state rotational excitation of CO by H2 near 1000 cm−1 collision energy

Far-infrared rotational emission by carbon monoxide

Contact Info

Product

Resources

About

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar

Dissipation of post‐pulse laser‐induced alignment of CO₂ through collisions with Ar