H2-broadening, shifting and mixing coefficients of the doublets in the ν2 and ν4 bands of PH3 at room temperature

Salem, Jamel; Blanquet, Ghislain; Lepère, Muriel; Younès, Rached Ben

doi:10.1080/00268976.2017.1423125

Cited by 3 publications

(9 citation statements)

References 30 publications

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“…Figure 3 gives qualitative examples showing the difference between: the intensities distribution in two overlapping lines: B 1 Y U S obtained in this work, and the line intensities presented with their errors B t ∆B deduced from the results of Ref. [18]. These examples are presented for the A 1 and A 2 lines of the doublets Q R (8, 3) in the ν 2 band and R R (4, 3) in the ν 4 band of PH 3 vs the square of the pressure of hydrogen U vk )h' U .…”

Section: Line Intensitiesmentioning

confidence: 81%

“…C , U R. C , C , P C and U S C parameters are related to the diagonal (\ CC ) and off-diagonal ( \ CCm with n′ p n ) elements of the collisional relaxation matrix (\) [19]. If the second-order parameters (R. C and S C ) equals to zero, then Equation (3) reduce to the expression of first-order Rosenkranz approximation model (VPI1) [18,27]. To fit the observed spectra, we have set the intensity parameter to the value deduced from the absolute line intensity of Ref.…”

Section: Profiles and Fitting Proceduresmentioning

confidence: 99%

“…To fit the observed spectra, we have set the intensity parameter to the value deduced from the absolute line intensity of Ref. [18]. Figure 2 shows an example of the fits for the A 1 and A 2 lines of the doublet R R (4, 3) in the ν 4 band of PH 3 diluted with 100.77 mbar of H 2 by theoretical profiles: VPI1 and VPI2.…”

Section: Profiles and Fitting Proceduresmentioning

confidence: 99%

“…Using the absolute line intensities B : 10 q r' U )h' / of Ref. [18], the absorption path length s and the constant partial pressure of PH 3 in the gas mixtures, we have deduced the intensity parameter B 10 q r' / for each studied transition. This parameter is fixed in the used fit profiles for all four recorded spectra broadened by four different H 2 pressures.…”

Section: Line Intensitiesmentioning

confidence: 99%

“…The same applies to the intensity parameter vs the pressure of the active gas. On the other hand, the lineshift shows in some papers a non-linear variation with the perturber pressure [14,17,18], which is incoherent with the hypotheses of the isolated lines and first-order Rosenkranz approximations. In fact, the reconstruction of the collisional profiles is based on the diagonalization of the relaxation matrix as part of the impact approximation.…”

Section: Introductionmentioning

confidence: 97%

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Infrared Line Collisional Parameters of PH3 in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Salem¹,

Younès²

2020

SJC

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Measurement of room temperature absorption by PH 3 -H 2 mixtures in the ν 2 and ν 4 bands of phosphine (PH 3 ) have been made for low pressures. Fits of these spectra are made for the determination of the width for isolated lines, and line mixing in first-order Rosenkranz approximation. From the previous determinations, we deduce some remarks on the lack of accuracy for the prediction of the collisional process. With the first-order Rosenkranz approximation, the collisional parameters are considered linear with pressure. In this work, we have considered some spectra recorded for three doublets A 1 and A 2 lines in the ν 2 and ν 4 bands of PH 3 diluted with higher H 2 pressure. We show that the line shifts are non-linear with perturber pressures, which requires testing the fits of the recorded spectra by profiles developed in the second-order approximation of the perturbation theory. Consequently, the first and second-order mixing coefficients are determined and discussed. Also, through this study, we show that the change of the intensities distribution is provided by the populations exchange between the low energy levels for the two components of doublets A 1 and A 2 lines and is described through the second-order mixing parameter. Thereby, we show the mixing effect on the line width.

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Section: Line Intensitiesmentioning

confidence: 81%

Section: Profiles and Fitting Proceduresmentioning

confidence: 99%

Section: Profiles and Fitting Proceduresmentioning

confidence: 99%

Section: Line Intensitiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

See 3 more Smart Citations

Infrared Line Collisional Parameters of PH3 in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Salem¹,

Younès²

2020

SJC

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Infrared Line Collisional Parameters of PH3 in Hydrogen: Measurements with Second-Order Approximation of Perturbation Theory

2021

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Line shape parameters of PH3 transitions: Theoretical studies of self-broadened widths and line mixing effects

Boulet

2020

The Journal of Chemical Physics

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Line mixing effects have been calculated in various parallel and perpendicular bands of self-broadened PH 3 lines and compared with recent experimental data. The theoretical approach is an extension to symmetric tops with high inversion barrier of the formalism previously developed for NH 3 [Q. Ma and C. Boulet, J. Chem. Phys. 144, 224303 (2016)]. The model takes into account the non-diagonality of the scattering operator within the line space as well as, in a correct way, the double degeneracy of the j, k levels when k ≠ 0. Transitions between such levels should be considered as doublets whose components may be coupled by the line mixing process. It has been shown that, at low pressure, the inversion of the experimental data will strongly depend on the splitting between the two components of a doublet. When it is significant, one can measure independently both the width of one component and the intra-doublet coupling matrix element. Otherwise, one can only measure the sum of these two elements. Comparisons with measurements show that the present formalism leads to accurate predictions of the experimental line shapes.

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H₂-broadening, shifting and mixing coefficients of the doublets in the ν₂ and ν₄ bands of PH₃ at room temperature

Cited by 3 publications

References 30 publications

Infrared Line Collisional Parameters of PH<sub>3</sub> in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Infrared Line Collisional Parameters of PH<sub>3</sub> in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Infrared Line Collisional Parameters of PH3 in Hydrogen: Measurements with Second-Order Approximation of Perturbation Theory

Line shape parameters of PH3 transitions: Theoretical studies of self-broadened widths and line mixing effects

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H2-broadening, shifting and mixing coefficients of the doublets in the ν2 and ν4 bands of PH3 at room temperature

Cited by 3 publications

References 30 publications

Infrared Line Collisional Parameters of PH&lt;sub&gt;3&lt;/sub&gt; in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Infrared Line Collisional Parameters of PH&lt;sub&gt;3&lt;/sub&gt; in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Infrared Line Collisional Parameters of PH3 in Hydrogen: Measurements with Second-Order Approximation of Perturbation Theory

Line shape parameters of PH3 transitions: Theoretical studies of self-broadened widths and line mixing effects

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H₂-broadening, shifting and mixing coefficients of the doublets in the ν₂ and ν₄ bands of PH₃ at room temperature

Infrared Line Collisional Parameters of PH<sub>3</sub> in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory

Infrared Line Collisional Parameters of PH<sub>3</sub> in Hydrogen: Measurements with Second-order Approximation of Perturbation Theory