THE EFFECT OF COLLISIONS ON THE DOPPLER BROADENING OF SPECTRAL LINES

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.

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The Use of Fabry-Perot Filters for Spectral Scanning

Publications of the Astronomical Society of Australia ◽

10.1017/s132335800001198x ◽

1969 ◽

Vol 1 (6) ◽

pp. 293-294

Author(s):

M. D. Waterworth

Keyword(s):

Stellar Atmospheres ◽

Spectral Lines ◽

Resolving Power ◽

Doppler Broadening ◽

Collisional Broadening ◽

Fabry Perot

In designing a stellar spectrograph, it is pointless to exceed the resolving power necessary to obtain all the information from the spectrum of a star. This is limited mainly by atomic thermal motions, giving rise to the Doppler broadening of spectral lines, by turbulence and rotation of the stellar atmospheres in which the lines are formed, and by collisional broadening.

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LASER SPECTROSCOPY, PAST, PRESENT, AND PERHAPS FUTURE

International Journal of Modern Physics B ◽

10.1142/s0217979287000037 ◽

1987 ◽

Vol 01 (01) ◽

pp. 15-30

Author(s):

ARTHUR L. SCHAWLOW

Keyword(s):

Laser Spectroscopy ◽

Tunable Lasers ◽

Spectral Lines ◽

Single Atom ◽

Fundamental Constants ◽

Doppler Broadening ◽

Resonance Fluorescence

Historically, observations of the spectra of simple atoms have led to much of our understanding of the laws of physics. Recently, with tunable lasers, we are able to extend these observations with enormously increased resolution, sensitivity, and precision. There are a number of methods for overcoming the Doppler broadening of spectral lines. As little as a single atom can be observed and studied, by resonance fluorescence or photoionization. Complex spectra can be simplified in systematic ways by laser labeling of chosen levels. These and other advances in techniques are being applied to improve the measurement of fundamental constants, and to test the basic laws of physics.

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REDUCTION OF DOPPLER BROADENING OF SPECTRAL LINES IN FAST‐BEAM SPECTROSCOPY

Applied Physics Letters ◽

10.1063/1.1653502 ◽

1971 ◽

Vol 18 (11) ◽

pp. 477-479 ◽

Cited By ~ 80

Author(s):

John O. Stoner ◽

John A. Leavitt

Keyword(s):

Spectral Lines ◽

Doppler Broadening

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Importance of Combined Lorentz-Doppler Broadening in High-Temperature Radiative Heat Transfer Applications

Journal of Heat Transfer ◽

10.1115/1.1798951 ◽

2004 ◽

Vol 126 (5) ◽

pp. 858-861 ◽

Cited By ~ 19

Author(s):

Anquan Wang ◽

Michael F. Modest

Keyword(s):

Heat Transfer ◽

High Temperature ◽

Critical Temperature ◽

Absorption Coefficient ◽

Radiative Heat Transfer ◽

Total Pressure ◽

Radiative Heat ◽

Narrow Band ◽

Spectral Lines ◽

Doppler Broadening

The importance of combined Lorentz-Doppler (or Voigt) broadening of spectral lines in high-temperature radiative heat transfer applications is investigated. Employing narrow-band transmissivities as the criterion, the critical total pressure below which, and the critical temperature above which Doppler broadening has a significant effect on the absorption coefficient is established for gaseous H2O and CO2.

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TWO-PHOTON LASER SPECTROSCOPY OF ANTIPROTONIC HELIUM

International Journal of Modern Physics E ◽

10.1142/s0218301313300245 ◽

2013 ◽

Vol 22 (09) ◽

pp. 1330024

Author(s):

MASAKI HORI

Keyword(s):

Laser Spectroscopy ◽

Quantum Electrodynamics ◽

Spectral Lines ◽

Antiprotonic Helium ◽

Electron Mass ◽

Doppler Broadening ◽

Mass Ratio ◽

Helium Atoms ◽

Two Photon ◽

Three Body

The ASACUSA collaboration of CERN has recently carried out two-photon laser spectroscopy of antiprotonic helium atoms. Some nonlinear two-photon transitions of the antiproton at the deep UV wavelengths λ = 139.8–197.0 nm were excited by irradiating the atom with two counterpropagating laser beams. This reduced the thermal Doppler broadening in the observed spectral lines. Three transition frequencies were thus determined with fractional precisions of 2.3–5 parts in 109. By comparing the results with three-body quantum electrodynamics calculations, the antiproton-to-electron mass ratio was derived as 1836.1526736(23). In this paper, we briefly review these recent experimental results.

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