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.

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 ν3 vibration–rotation band of DCP and the equilibrium structure of methinophosphide

1982 ◽  
Vol 60 (3) ◽  
pp. 304-306 ◽  
Author(s):  
Jacques Lavigne ◽  
Aldée Cabana
Keyword(s):  
Force Constant ◽  
Rotational Constant ◽  
Equilibrium Structure ◽  
Moment Of Inertia ◽  
Rotation Band ◽  
A Value ◽  
Internuclear Distances ◽  
Vibration Rotation

The ν3 band of D12CP(C—P stretching) has been recorded at a resolution of about 0.03 cm−1. The band centre, ν0, is found to be at 1231.4025(6) cm−1, whereas a force constant calculation had previously given a value of 1216 cm−1. The rotational constant B3 is determined and this allows the calculation of Be since the constants B1 and B2 are already known. Finally, the equilibrium moment of inertia, Ie, of the D12CP molecule is calculated. Since Ie for the H12CP molecule is also known, the equilibrium internuclear distances of methinophosphide may be calculated. One obtains: re (C—H) 1.0666(2) Å, and re(C≡P) 1.54020(3) Å.

Emissivity Calculations for Diatomic Gases

1951 ◽  
Vol 18 (1) ◽  
pp. 53-58
Author(s):  
S. S. Penner
Keyword(s):  
Absorption Coefficient ◽  
Atmospheric Pressure ◽  
Radiant Heat ◽  
Published Data ◽  
Radiant Heat Transfer ◽  
Effective Width ◽  
Combustion Chambers ◽  
Average Absorption Coefficient ◽  
Vibration Rotation ◽  
Simplified Procedure

Abstract An approximate method for estimating radiant-heat transfer from gaseous emitters has been developed. An average absorption coefficient is used for an effective width of an entire vibration-rotation band. The procedure for determining an average absorption coefficient in terms of integrated absorption can be justified, approximately, for very large total pressures where the spectral half-width is no longer small compared with the rotational spacing. Because of this limitation, it is to be expected that the procedure proposed here will be particularly useful only in estimating gaseous emissivities for emitters in high-pressure combustion chambers. Nevertheless, it appears that the simplified procedure yields reasonable results even at relatively low total pressures. Thus a comparison of calculated and observed emissivities for CO at atmospheric pressure shows satisfactory agreement, especially at large optical densities. Representative emissivity calculations over a wide temperature range are described. Emissivity calculations on CO, NO, HF, HCl, HBr, and HI can be carried out very rapidly by the use of recently published data on these gases.

DERIVATIVES OF MONOGERMANE: PART I. THE VIBRATION–ROTATION SPECTRA OF GERMYL FLUORIDE AND BROMIDE

1962 ◽  
Vol 40 (4) ◽  
pp. 579-589 ◽  
Author(s):  
J. E. Griffiths ◽  
T. N. Srivastava ◽  
M. Onyszchuk
Keyword(s):  
Harmonic Oscillator ◽  
Infrared Absorption ◽  
Thermodynamic Functions ◽  
Low Frequency ◽  
Rotational Constant ◽  
Rigid Rotator ◽  
Harmonic Oscillator Model ◽  
Infrared Absorption Spectra ◽  
Vibration Rotation ◽  
Derivatives Of

The vibration–rotation infrared absorption spectra of germyl fluoride and bromide have been observed. All of the fundamentals in GeH3F were located, and the rotational structure of the E-type bands were resolved and analyzed. The low-frequency band, ν3(a1), in GeH3Br was not observed but an estimate of its position was made from the frequencies of the combination band ν3 + ν6 and of ν6. The rotational constant A″ and the Coriolis constants ζ4, ζ5, and ζ6 were calculated for both molecules, and agreement with microwave A″ values was satisfactory. Thermodynamic functions based upon a rigid-rotator, harmonic-oscillator model have been evaluated for germyl fluoride and bromide.

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.

Diode Laser Spectrum of HCCCN near 5 μm

1980 ◽  
Vol 35 (7) ◽  
pp. 690-693 ◽  
Author(s):  
Koichi Yamada ◽  
R. Schieder ◽  
G. Winnewisser ◽  
A. W. Mantz
Keyword(s):  
Excited State ◽  
Diode Laser ◽  
Rotational Constant ◽  
Doppler Broadening ◽  
Laser Spectrometer ◽  
Laser Spectrum ◽  
Band Center ◽  
Diode Laser Spectrometer ◽  
Vibration Rotation ◽  
Better Than

The ν3 vibration-rotation band of cyanoacetylene, HC3N, has been measured in the wavenumber range 2068 to 2095 cm-1 to an accuracy of better than ± 0.005 cm-1 using a diode laser spectrometer. The width of the observed lines is essentially limited by Doppler-broadening. The band center of the ν3 vibration is determined from the observed P- and R-branch transitions to be at 2079.30500 (58) cm-1. The rotational constant of the excited state is B′= 0.151212 (10) cm-1.

Diode Laser Spectrum of HCCCN: CN Stretching Band

1983 ◽  
Vol 38 (12) ◽  
pp. 1296-1308 ◽  
Author(s):  
Koichi Yamada ◽  
Regina Best ◽  
G. Winnewisser
Keyword(s):  
Diode Laser ◽  
Accurate Determination ◽  
Rotational Constant ◽  
Centrifugal Distortion ◽  
Laser Spectrum ◽  
Diode Laser Spectroscopy ◽  
Vibration Rotation ◽  
Wavenumber Region ◽  
Estimated Error

Abstract The ν2 vibration-rotation band of cyanoacetylene. HCCCN, has been studied by diode laser spectroscopy in the wavenumber region from 2240 cm-1 to 2290 cm-1. In addition to the fundamental band we have assigned hot bands arising from v7 = 1. 2. and 3 states and from v6 = 1 state. In these hot bands splittings due to l-type doubling and l-type resonance were clearly observed. The transition wavenumbers were measured precisely, with an estimated error of 0.001 cm-1. Their analysis simultaneously with the microwave data allowed an accurate determination of the band origin v0 = 2273.99539(11) cm-1, the rotational constant B′ = 4527.4861 (28) MHz. and the centrifugal distortion constant D′ = 0.53547(43) kHz.

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 .

Laser fluorescence and high vibrational levels of 15NO2

1979 ◽  
Vol 57 (6) ◽  
pp. 828-835 ◽  
Author(s):  
J. C. D. Brand ◽  
P.-H. Chiu ◽  
A. R. Hoy
Keyword(s):  
Magnetic Resonance ◽  
Ground State ◽  
Narrow Band ◽  
Laser Fluorescence ◽  
Resonance Fluorescence ◽  
Infrared Measurements ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Laser Magnetic Resonance ◽  
Electronic Ground

Resonance fluorescence of 15NO2 excited by narrow-band radiation of an Ar+ laser at 514, 495, 488, and 476 nm is reported and analyzed. The data are combined with published laser magnetic resonance and infrared measurements to obtain a set of vibration and vibration–rotation constants for the electronic ground state of this isotope.The fluorescence bands reported are a-axis polarized, corresponding to a transition moment [Formula: see text] between 2B2 and 2A1 basis states. Numerous anomalies in the vibrational and rotational structure of the fluorescence indicate that, in the region of the manifold probed by the laser, vibrational levels of the parent 2B2 basis state mix extensively with one another as well as with high vibrational levels of the 2A1 ground state.

Die Bestimmung von Molekülkonstanten aus nicht aufgelösten Bandenspektren am Beispiel des PO-β-Systems

1966 ◽  
Vol 21 (11) ◽  
pp. 1878-1883
Author(s):  
H. Meinel ◽  
L. Krauss
Keyword(s):  
Correction Term ◽  
Rotational Constant ◽  
Nuclear Motion ◽  
Cubic Equation ◽  
System A ◽  
Quantum Numbers ◽  
Vibrational Levels ◽  
Doublet Splitting ◽  
Potential Curves

For 2∑-2Πa transitions (e. g. PO β-system), a method is described for calculation of rotational constants B (ν) from the doublet splitting of the bandheads. In that way the classification of both the violet and the red shaded PO β-bands (some 30 bands are new analysed) into one system can be shown, which seemed to be doubtful recently. From the discrepancies between the observed and the calculated additional heads in some subbands the rotational constant D has been evaluated, which plays an important part particularly for higher values of J as correction term in our calculation. Small systematic deviations in the graph of the rotational constant B (ν) for some sequences Δν=ν′-ν″ are interpreted as an indication for the interaction between electronic and nuclear motion; the effect corresponds to a deformation in the flanks of the potential curve in the order of 0.001 Å for higher vibrational quantum numbers (ν>5). The potential curves for the PO β- and γ-system have been computed, and from their relative position the observed perturbation of the level ν′=10 (β-system) and the range of perturbation starting at ν′=0 (γ-system) is explained. By calculation of the band origins a cubic equation for the vibrational levels of the B2∑-state is deduced. The extrapolation of the differences between two successive vibrational levels yields a new value of dissociation energy D00 (PO) =5.15 eV.

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