Theory of Fine Structure Pressure Broadening of Spectral Lines

1954 ◽  
Vol 93 (3) ◽  
pp. 420-424 ◽  
Author(s):  
Makoto Takeo ◽  
Shang-Yi Ch'en
Keyword(s):  
Fine Structure ◽  
Spectral Lines ◽  
Pressure Broadening

Broadening of the Fine-Structure Raman Lines in Gaseous Oxygen

1971 ◽  
Vol 26 (10) ◽  
pp. 1639-1643
Author(s):  
S. Hess ◽  
H. F. P. Knaap
Keyword(s):  
Fine Structure ◽  
Relaxation Frequency ◽  
Collision Term ◽  
60 Ghz ◽  
Pressure Broadening ◽  
Gaseous Oxygen ◽  
Molecular Potential ◽  
Electronic Spin ◽  
Anti Stokes ◽  
Rayleigh Light

Abstract Due to the coupling between the rotational angular momentum and the electronic spin, the depolarized Rayleigh light scattered from gaseous oxygen shows Stokes and anti-Stokes satellites shifted by about 60 GHz. The broadening of these fine-structure Raman lines is investigated theoretically for high and medium pressures where the linewidth is determined by two contributions, one proportional and the other inversely proportional to the pressure, p. The linewidth in the pressure broadening region is given by a relaxation frequency which is obtained from the Waldmann-Snider collision term. The p-1 contribution to the linewidth is determined by the ratio of the second moment of the fine-structure freqencies (with respect to the center of the shifted line) and another relaxation frequency. Both relaxation frequencies are sensitive to the nonspherical part of the inter-molecular potential.

Profiles of Pressure Broadened Spectral Lines in an Arc Plasma

2005 ◽  
Vol 60 (10) ◽  
pp. 727-735
Author(s):  
Reda A. El-Koramy ◽  
Abd El-Halim A. Turky
Keyword(s):  
Alkali Metals ◽  
Stark Effect ◽  
Point Of View ◽  
Spectral Lines ◽  
Pressure Broadening ◽  
Static Approximation ◽  
Pressure Line ◽  
Pressure Profiles ◽  
Impact Approximation ◽  
Quadratic Stark Effect

Spectral analysis of the alkali metals is characterized by pressure profiles. In the present work an electric arc has been used to calibrate the half-width of the intensity used in the construction of the ArI natural line at 4300 Å with a trace of evaporated rubidium at pressures of 1, 2 and 3 atmospheres. The results agree well with those obtained by Kusch’s line absorption equation in an electric furnace in the point of view of impact approximation, showing that the widths of the lines have Lorentz shapes. It is found that a simple treatment can be given using the quasi-static approximation of pressure broadening developed by Unsöld. The agreement of the results is good only if the shifts are large. The study shows that the pressure line profile is made up of a sum of dispersion profiles and asymmetric terms which arise from interactions of quadratic Stark effect, commonly assumed to be the force in causing foreign gas broadening

General Theory of Pressure Broadening of Spectral Lines

1945 ◽  
Vol 68 (3-4) ◽  
pp. 78-93 ◽  
Author(s):  
Alexander Jabloński
Keyword(s):  
General Theory ◽  
Spectral Lines ◽  
Pressure Broadening

Theory of Pressure Broadening of Microwave Spectral Lines

1969 ◽  
Vol 182 (1) ◽  
pp. 24-38 ◽  
Author(s):  
Joel I. Gersten ◽  
Henry M. Foley
Keyword(s):  
Spectral Lines ◽  
Pressure Broadening

On the combined Doppler and pressure broadening of nonresonant spectral lines

1988 ◽  
Vol 66 (4) ◽  
pp. 341-348
Author(s):  
M. A. Diaz ◽  
F. Palomares ◽  
J. Veguillas
Keyword(s):  
Kinetic Equation ◽  
Inelastic Collisions ◽  
Spectral Lines ◽  
The Other ◽  
Low Density ◽  
Doppler Broadening ◽  
Equation Approach ◽  
Pressure Broadening ◽  
Debye Relaxation ◽  
Collision Model

An explicit spectral function for nonresonant transitions has been derived that includes pressure broadening, Doppler broadening, and diffusional narrowing. This has been accomplished through a kinetic-equation approach. The kinetic equation has been resolved by using an extension of the Bhatnagar–Gross–Krook collision model to inelastic collisions, characterized by two collision frequencies: one associated with elastic collisions and the other associated with inelastic ones. The high- and low-density limits have been discussed, and the standard formula for Debye relaxation has been reproduced. Finally, a discussion concerning the above aspects and their possible extensions has been included as well.

scholarly journals Numerical Simulation of Granular Convection: Effects on Photospheric Spectral Line Profiles

1980 ◽  
Vol 51 ◽  
pp. 213-224
Author(s):  
Åke Nordlund
Keyword(s):  
Spectral Line ◽  
Line Strength ◽  
Blue Shift ◽  
Spectral Lines ◽  
Line Profiles ◽  
Pressure Broadening ◽  
Solar Granulation ◽  
Velocity Fluctuations ◽  
Excitation Potential ◽  
On Line

AbstractThe results of numerical simulations of the solar granulation are used to investigate the effects on photospheric apectral lines of the correlated velocity and temperature fluctuations of the convective granular motions. It is verified that the granular velocity field is the main cause for the observed broadening and strengthening of photospheric spectral lines relative to values expected from pure thermal and pressure broadening. These effects are normally referred to as being due to “macro-turbulence” and “micro-turbulence”, respectively. It is also shown that the correlated temperature and velocity fluctuations produce a “convective blue shift” in agreement with the observed blue shift of photospheric spectral lines. Reasons are given for the characteristic shapes of spectral line bisectors, and the dependence of these shapes on line strength, excitation potential, and center to limb distance are discussed.

Pressure Broadening of Spectral Lines

1950 ◽  
Vol 79 (4) ◽  
pp. 744-744 ◽  
Author(s):  
T. Holstein
Keyword(s):  
Spectral Lines ◽  
Pressure Broadening
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