Etude des intensités et des largeurs des raies de vibration–rotation de la bande deuxième harmonique de l'anhydride carbonique à 6970 cm−1 par déconvolution numérique

1968 ◽  
Vol 46 (15) ◽  
pp. 1697-1703 ◽  
Author(s):  
Philippe Arcas ◽  
Lucette Hochard-Demolliere
Keyword(s):  
Line Width ◽  
Half Width ◽  
Numerical Calculations ◽  
Instrumental Effects ◽  
Curve Versus ◽  
Variation Curve ◽  
Vibration Rotation

The intensity and half-width of the 12CO2 3ν3 band lines are determined, the instrumental effects being corrected by numerical calculations. The square of the vibrational moment (R03)2 is found to be equal to 0.233 × 10−42 e.s.u. With a quadrupolar momentum Q = 5.2 × 10−26 e.s.u., the line-width variation curve versus J can be approximately interpreted by Anderson's theory.

Properties of Digital Smoothing Polynomial (DISPO) Filters

1981 ◽  
Vol 35 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Horst Ziegler
Keyword(s):  
Noise Reduction ◽  
Real Time ◽  
Line Width ◽  
Time Constant ◽  
Fourth Order ◽  
Digital Filters ◽  
Half Width ◽  
Line Shift ◽  
Scan Speed

Digital filters for spectrometric applications are compared with the classical RC filter. Properties discussed include noise reduction, line shift, and conservation of line moments. For Gaussian and Lorentzian lines, signal deformation and change of half-width as a function of time constant and line width are calculated for several filter types. Using accuracy, sensitivity, and scan speed as criteria, it is shown that a fourth-order digital smoothing polynomial (DISPO) filter is better by typically 1 or even 2 orders of magnitude than the RC filter. Since a real time implementation of these filters is possible, they can directly replace RC filters in all spectrometric applications.

REFRACTION SPECTRUM OF GASES IN THE INFRARED INTENSITIES AND WIDTHS OF LINES IN THE 2–0 BAND OF HCl

1962 ◽  
Vol 40 (1) ◽  
pp. 113-121 ◽  
Author(s):  
J. H. Jaffe ◽  
S. Kimel ◽  
M. A. Hirshfeld
Keyword(s):  
Absorption Spectrum ◽  
Resolving Power ◽  
Band Intensity ◽  
Instrumental Effects ◽  
Infrared Intensities ◽  
Vibration Rotation ◽  
Rotation Constant

Intensities and widths of lines in the 2–0 band of HCl have been determined from the refraction spectrum. A hollow prism refractometer was used together with a monochromator of high resolving power. Fairly elaborate corrections for instrumental effects were applied to the observations. A band intensity of 3.68 cm−2 atm−1 was obtained. The vibration–rotation constant θ was found to be 0.97. Both these values agree well with recent results for HCl obtained from the absorption spectrum.

Microphotometric Errors for Photographically Recorded Spectral Lines of Nonuniform Half-Width

1978 ◽  
Vol 32 (5) ◽  
pp. 433-444 ◽  
Author(s):  
L. C. McGonagle ◽  
J. A. Holcombe
Keyword(s):  
Line Width ◽  
Half Width ◽  
Slit Width ◽  
Spectral Lines ◽  
Average Error ◽  
Spatially Resolved ◽  
Source Line ◽  
Line Widths ◽  
Spectrometer Slit ◽  
The Impact

Various microphotometric (or densitometric) techniques for generating quantitative intensity information from photographically recorded spectral lines of time or spatially resolved sources are discussed. The impact of various parameters on the accuracy of quantitative densitometry is presented. These parameters include line widths of the calibration spectrum, source line broadening, microphotometer scan slit width and the optical density of the photographic image. Nonrandom errors associated with the use of various microphotometer slit widths for spectral lines of nonuniform half-width are presented. Spectral lines which are uniform and exhibit slit width or diffraction limited resolution can be scanned with any size microphotometer slit width as long as the calibration curve is prepared using the same scan slit width. The use of microphotometer slit widths narrower than the line width produce H and D curves with maximal γ and increased accuracy in the final intensity value. A density-to-intensity conversion accuracy with a 6% average error was determined for SA-1 plates. For sources whose line widths are larger than the spectrometer bandpass, minimal errors are generated by using a narrow line source for calibration and scanning this spectrum with a slit width less than the line width. Scanning of the broadened line of interest is accomplished using a scan slit width equal to approximately twice the spectrometer slit width. Under these conditions an average error of approximately 11% was determined experimentally for SA-1 plates.

Pressure broadening studies on vibration-rotation bands, IV. Optical collision diameters for foreign-gas broadening of CO and DCl bands

1963 ◽  
Vol 272 (1351) ◽  
pp. 453-466 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Quantum Number ◽  
Line Width ◽  
Interaction Potential ◽  
Similar Data ◽  
Dispersion Forces ◽  
Pressure Broadening ◽  
Interaction Forces ◽  
Deuterium Chloride ◽  
Vibration Rotation

Results are given for the pressure broadening of lines in the vibration-rotation bands of carbon monoxide and deuterium chloride, by a wide variety of added gases including both non-polar and polar molecules. Optical collision diameters have been calculated and considered in relation to the interaction forces likely to be involved. For carbon monoxide, a rough correlation is found between the optical collision diameter and the interaction potential for non-polar broadeners where dispersion forces are dominant, but derivations occur with some polar broadeners. Similar data for deuterium chloride illustrate the importance of dipolar forces, but no simple theory explains the results satisfactorily. The variation of line width with J quantum number is discussed.

Water vapor line width and shift calculations with accurate vibration–rotation wave functions

2008 ◽  
Vol 109 (10) ◽  
pp. 1834-1844 ◽  
Author(s):  
A.D. Bykov ◽  
N.N. Lavrentieva ◽  
T.P. Mishina ◽  
L.N. Sinitsa ◽  
R.J. Barber ◽  
...  
Keyword(s):  
Water Vapor ◽  
Line Width ◽  
Wave Functions ◽  
Vapor Line ◽  
Vibration Rotation

On The Radii of Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 49-55 ◽  
Author(s):  
F.A. Catalano ◽  
G. Strazzulla
Keyword(s):  
Observational Data ◽  
Line Width ◽  
Main Sequence ◽  
Main Sequence Stars ◽  
Ap Stars

SummaryFrom the analysis of the observational data of about 100 Ap stars, the radii have been computed under the assumption that Ap are main sequence stars. Radii range from 1.4 to 4.9 solar units. These values are all compatible with the Deutsch's period versus line-width relation.

LVSEM: Past Present and Future

1990 ◽  
Vol 48 (1) ◽  
pp. 364-365
Author(s):  
James B. Pawley
Keyword(s):  
Field Emission ◽  
Line Width ◽  
Time Scales ◽  
Silicon Oxide ◽  
Beam Current ◽  
High Brightness ◽  
High Beam ◽  
Fixed Charges ◽  
Beam Voltage ◽  
Deposited Metal

Past: In 1960 Thornley published the first description of SEM studies carried out at low beam voltage (LVSEM, 1-5 kV). The aim was to reduce charging on insulators but increased contrast and difficulties with low beam current and frozen biological specimens were also noted. These disadvantages prevented widespread use of LVSEM except by a few enthusiasts such as Boyde. An exception was its use in connection with studies in which biological specimens were dissected in the SEM as this process destroyed the conducting films and produced charging unless LVSEM was used.In the 1980’s field emission (FE) SEM’s came into more common use. The high brightness and smaller energy spread characteristic of the FE-SEM’s greatly reduced the practical resolution penalty associated with LVSEM and the number of investigators taking advantage of the technique rapidly expanded; led by those studying semiconductors. In semiconductor research, the SEM is used to measure the line-width of the deposited metal conductors and of the features of the photo-resist used to form them. In addition, the SEM is used to measure the surface potentials of operating circuits with sub-micrometer resolution and on pico-second time scales. Because high beam voltages destroy semiconductors by injecting fixed charges into silicon oxide insulators, these studies must be performed using LVSEM where the beam does not penetrate so far.

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