Correlation effects in the theory of combined doppler and pressure broadening—I. Classical theory

Ward, J.; Cooper, J.; Smith, Elizabeth S.

doi:10.1016/0022-4073(74)90036-3

Cited by 225 publications

(101 citation statements)

References 46 publications

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“…3 was based on the Voigt profile, which failed to describe the observed line shape. This can be attributed to the fact that the Voigt profile assumes that molecular collisions which lead to pressure broadening and shifts are velocity independent and that the molecules follow simple straight-line trajectories [25][26][27]. However, since the dimensions of the nanopores used in this study are significantly smaller than the wavelength of the light, and the perturber mass, i.e., the walls, is much larger than the mass of the O 2 molecule, Dicke-type narrowing effects [28,29] may partly explain the deviation.…”

Section: Resultsmentioning

confidence: 99%

Wall-collision line broadening of molecular oxygen within nanoporous materials

Lewander

Andersson‐Engels

et al. 2011

Phys. Rev. A

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Section: Resultsmentioning

confidence: 99%

Wall-collision line broadening of molecular oxygen within nanoporous materials

Lewander

Andersson‐Engels

et al. 2011

Phys. Rev. A

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“…We additionally tested the speed-dependent Voigt profile (SDVP) [32], which includes the speed dependence of collisional broadening and shifting but neglects the velocity changing collisions. Speed dependence of the line-shape parameters was described either in terms of quadratic approximation [33] or with confluent hypergeometric functions [34], which we denote in the profile name abbreviation by subscripts 'q' and 'h', respectively. Unperturbed line positions and collisional shift coefficients derived with all above models were compared to the values extracted by fitting the simple Voigt profile (VP).…”

Section: Measurements and Data Analysismentioning

confidence: 99%

Absolute frequency determination of molecular transition in the Doppler regime at kHz level of accuracy

Bielska

Wójtewicz

Morzynski

et al. 2017

Journal of Quantitative Spectroscopy and Radiative Transfer

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We measured absolute frequency of the unperturbed P7 P7 O2 B-band transition ν0 = 434783.5084857(82) GHz and the collisional self-shift coefficient δ = −9.381(62) × 10 −21 GHz/(molecule/cm 3 ). With Doppler-limited spectroscopy we achieved the relative standard uncertainty of 2 × 10 −11 on line position, typical for Doppler-free techniques. Shapes of the spectral line were measured with a Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectrometer referenced to an 88 Sr optical atomic clock via an optical frequency comb.

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“…In this case, the collision operator can be written 53 The speed dependence of collisional broadening and shifting is described by the dimensionless functions B W (x) and B S (x), with x = v/v m the absorber reduced speed. 8,68 Dimensionless functions B W (x) and B S (x) for H 2 2-0 Q(1) line are not known. Therefore, like Tran et al, 51 we described the speed dependence of the broadening and shifting using an empirical relation explored for the H 2 1-0 band by Forsman et al 69 The B S (x) function was adjusted to properly reproduce magnitude of collisional shift 70,71 of the measured spectral line, see Appendix C for details.…”

Section: B Spectral Analysismentioning

confidence: 99%

“…The speed dependence of collisional broadening and shifting is described by the dimensionless functions B W (x) and B S (x) defined as: 8,68 …”

Section: Appendix B: Autocorrelation Functions For Hard and Soft Collmentioning

confidence: 99%

Velocity-changing collisions in pure H2 and H2-Ar mixture

Wcisło

Tran

Kassi

et al. 2014

The Journal of Chemical Physics

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We show how to effectively introduce a proper description of the velocity-changing collisions into the model of isolated molecular transition for the case of self-and Ar-perturbed H 2 . We demonstrate that the billiardball (BB) approximation of the H 2 -H 2 and H 2 -Ar potentials gives an accurate description of the velocitychanging collisions. The BB model results are compared with ab initio classical molecular dynamics simulations (CMDS). It is shown that the BB model correctly reproduces not only the principal properties such as frequencies of velocity-changing collisions or collision kernels, but also other characteristics of H 2 -H 2 and H 2 -Ar gas kinetics like rate of speed-changing collisions. Finally, we present line-shape measurement of Q (1) line of the first overtone band of self-perturbed H 2 . We quantify the systematic errors of line-shape analysis caused by the use of oversimplified description of velocity-changing collisions. These conclusions will have significant impact on recent rapidly developing ultra-accurate metrology based on Doppler-limited spectroscopic measurements like Doppler-width thermometry, atmosphere monitoring, Boltzmann constant determination or transition position and intensity determination for fundamental studies.

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Correlation effects in the theory of combined doppler and pressure broadening—I. Classical theory

Cited by 225 publications

References 46 publications

Wall-collision line broadening of molecular oxygen within nanoporous materials

Wall-collision line broadening of molecular oxygen within nanoporous materials

Absolute frequency determination of molecular transition in the Doppler regime at kHz level of accuracy

Velocity-changing collisions in pure H2 and H2-Ar mixture

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