Vibrational population distribution in the hydroxyl night airglow

1983 ◽  
Vol 61 (2) ◽  
pp. 244-250 ◽  
Author(s):  
D. N. Turnbull ◽  
R. P. Lowe
Keyword(s):  
Population Distribution ◽  
Fourier Transform Spectrometer ◽  
Excitation Mechanism ◽  
Line Intensities ◽  
Vibrational Levels ◽  
Water Vapour Absorption ◽  
Vibration Rotation ◽  
A New Technique ◽  
Vibrational Population ◽  
Night Airglow

Relative populations of the vibrational levels ν = 2 to ν = 9 (except ν = 5) of the hydroxyl radical have been determined from observations of the Δν = 2 and 3 sequences of the vibration–rotation bands in the infrared night airglow spectrum using a Fourier transform spectrometer. The observed line intensities were corrected for water vapour absorption using a new technique. The results indicate a population of the upper vibrational levels which is as much as a factor of two lower than that found in other studies. The observed distribution is not consistent with the atomic hydrogen ozone reaction being the sole excitation mechanism in the night airglow unless the quenching and other rates used in our model are in error.

Quantitative spectroscopy of the aurora. IV. The spectrum of medium intensity aurora between 8800 Å and 11 400 Å

1976 ◽  
Vol 54 (21) ◽  
pp. 2128-2133 ◽  
Author(s):  
A. Vallance Jones ◽  
R. L. Gattinger
Keyword(s):  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Positive System ◽  
Rotation System ◽  
Intensity Measurements ◽  
Medium Intensity ◽  
Vibrational Levels ◽  
Condon Factors ◽  
Vibration Rotation ◽  
Vibrational Population

An averaged spectrum of medium intensity aurora (I(4278 Å) ≈ 20 kR) at a resolution of 15 Å from 8800 Å to 11 400 Å is presented. The observations were made with a grating spectrometer and S1 photomultiplier detector. Synthetic comparison spectra were prepared to aid in the identification and relative intensity measurements of the observed emission features. Included in the synthesis were the nitrogen first positive, Meinel, and infrared afterglow systems, the oxygen atmospheric system, the hydroxyl vibration–rotation system, and a number of atomic emissions. Three unidentified features have been tentatively ascribed to NI multiplets. Comparisons have been made between the observed and theoretically calculated relative populations of the four lowest vibrational levels in the upper electronic states of both the nitrogen first positive and Meinel systems. The relative vibrational populations of N2(B3Π) do not fit the hypothesis of direct electron impact excitation plus cascade through the N2 second positive system. The relative vibrational population rates of the Meinel N2+ system deviate from the Franck–Condon factors for the excitation transition.

The vibrational population distribution of H 2 +. formed from a series of different precursor molecules

1984 ◽  
Vol 395 (1808) ◽  
pp. 111-125 ◽  
Keyword(s):  
Population Distribution ◽  
Kinetic Energy Release ◽  
Hydrogen Gas ◽  
Small Deviations ◽  
Population Distributions ◽  
Vibrational Levels ◽  
Product Ions ◽  
Vibrational Population ◽  
Precursor Molecules ◽  
Kinetic Energy Release Distribution

The collision induced spectra of H 2 +. → H + have been measured by translational spectroscopy, where the hydrogen molecular ion was formed from a series of hydrogen-containing precursors. Differences in the shapes of the collision-induced spectra were observed, which reflect upon the initial vibrational distributions in which H 2 +. was formed. These distri­butions were calculated, for each precursor, by associating to each vibrational level an individual kinetic energy release distribution, from which the experimentally observed spectra were regenerated by a computer simulation. Each calculated distribution was normalized to a previously published vibronic distribution obtained from a photo­dissociation study of H 2 +. . The vibrational population distributions of H 2 +. product ions, for each precursor, show small deviations, for v ≼ 12, from that obtained when hydrogen gas was the precursor, and differences of between a factor 0.8 to 3 for higher vibrational levels.

Vibration-rotation bands and rotational constants of dideuteroacetylene

1955 ◽  
Vol 232 (1190) ◽  
pp. 291-309 ◽  
Keyword(s):  
Resolving Power ◽  
Vibrational States ◽  
Absorption Bands ◽  
Rotational Constants ◽  
Vibrational Assignments ◽  
Vibrational Anharmonicity ◽  
A Value ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Very High

Nine vibrational absorption bands of dideutero-acetylene have been examined with very high resolving power. The rotational constants have been determined for the vibrational levels concerned, and the coefficients α i have been determined with more convincing accuracy than previously. In some of the bands the Q branches have been resolved, so that the l -doubling coefficients q i could be derived, and details could be established about the doublet components in some II levels. The results emphasize the need of high resolution if the vibrational assignments are to be unambiguous, and if reliable values of the rotational constants are to be derived. A value of B e has been obtained, and the vibrational anharmonicity coefficients have been considered briefly. Estimates of the centrifugal stretching constants D i in different vibrational states have been made, and one anomalous case has been found.

The infrared spectrum of CS

1984 ◽  
Vol 62 (12) ◽  
pp. 1414-1419 ◽  
Author(s):  
R. J. Winkel Jr. ◽  
Sumner P. Davis ◽  
Rubén Pecyner ◽  
James W. Brault
Keyword(s):  
Fourier Transform ◽  
Infrared Emission ◽  
Solar Observatory ◽  
Band Head ◽  
The Other ◽  
Fourier Transform Spectrometer ◽  
National Solar Observatory ◽  
Carbon Monosulfide ◽  
Vibration Rotation ◽  
The Fourier Transform

The infrared emission spectrum of carbon monosulfide was observed as a sequence of vibration–rotation bands in the X1Σ+ state, with strong heads of the Δν = 2 sequence degraded to the red. Eight bands of 12C32S were identified, and bands corresponding to the isotope 12C34S were also observed. The most prominent band head, that of the (2–0) band, is at 2585 cm−1, with the other heads spaced approximately 26 cm−1 to smaller wavenumbers. Our data, taken with the Fourier transform spectrometer at the National Solar Observatory (Kitt Peak) include the first reported laboratory observations of the band heads and as many as 200 lines in each band. These observations allowed the calculation of vibrational and rotational constants to higher order than previously reported.

scholarly journals Comparison of HF and HCl Chemical Laser Parameters by using Mathematical Model

2007 ◽  
Vol 4 (1) ◽  
pp. 119-124
Author(s):  
Baghdad Science Journal
Keyword(s):  
Computer Program ◽  
Parametric Analysis ◽  
Rotational Constant ◽  
Published Data ◽  
Vibrational Quantum Number ◽  
Theoretical Comparison ◽  
Fabry Perot ◽  
Vibrational Levels ◽  
Hf Laser ◽  
Vibration Rotation

A simplified theoretical comparison of the hydrogen chloride (HCl) and hydrogen fluoride (HF) chemical lasers is presented by using computer program. The program is able to predict quantitative variations of the laser characteristics as a function of rotational and vibrational quantum number. Lasing is assumed to occur in a Fabry-Perot cavity on vibration-rotation transitions between two vibrational levels of hypothetical diatomic molecule. This study include a comprehensive parametric analysis that indicates that the large rotational constant of HF laser in comparison with HCl laser makes it relatively easy to satisfy the partial inversion criterion. The results of this computer program proved their credibility when compared with the little published data.

scholarly journals Calculations of CO2 Energy Levels: The Ã1B2 State

1971 ◽  
Vol 40 ◽  
pp. 43-43
Author(s):  
W. S. Benedict
Keyword(s):  
Carbon Monoxide ◽  
Energy Levels ◽  
Vibrational Levels ◽  
Upper Level ◽  
Vibration Rotation

The Ã1B2 state of CO2, identified by Dixon (1963) as the upper level of the ‘carbon monoxide flame bands’, must be of importance in the upper atmospheres of Venus and Mars. New calculations of the high vibrational levels of the ground state, which lead to improved fits of the observed vibration-rotation bands, confirm Dixon's analysis, except that the numbering must be lowered by two, and fix the energy of the v = 0, K = 0 level of 1B2 at 45210 ± 10 cm−1 = 5.605 eV.

Vibration-rotation bands of acetylene and the molecular dimensions

1956 ◽  
Vol 238 (1212) ◽  
pp. 15-30 ◽  
Keyword(s):  
Molecular Vibrations ◽  
Rotational Constants ◽  
Bond Lengths ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Molecular Dimensions

In view of recent inconsistencies in the relation between the bond lengths and rotational constants in the isotopic acetylenes, some vibration-rotation bands of acetylene have been re-measured, and the results have been analyzed together with earlier work on this molecule. The α values for each of the molecular vibrations have been re-determined, taking into account possible vibrational perturbations and also anomalous changes in the centrifugal stretching constant D of the different vibrational levels. The new values of α , 1 , α 2 , α 3 and ( α 4 + α 5 ) for acetylene are in line with the corresponding values for the deuterated derivatives, and using B o = 1·1766 lead to B e + 1·1817. If bond lengths r e (CH) = 1·058 5 , r e (CC) = l·204 7 Å are assumed, the results for all three isotopic molecules are mutually consistent. Values have also been obtained for the l -doubling coefficients, q 4 and q 5 .

Sign in / Sign up

Export Citation Format

Share Document