Doppler broadening


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Doppler broadening

(dop -ler) Broadening of spectral lines due to the random motion of emitting or absorbing atoms. As a result of the Doppler effect, atoms moving away from the observer show lines with a slight shift to longer wavelengths; atoms moving toward the observer show a slight shift to shorter wavelengths. The overall effect is that the line is broader than the natural width (determined by quantum mechanical uncertainty).

The motion of the atoms may be due to thermal motion, in which case the effect is larger for lighter atoms. Turbulence of stellar material, rapid rotation of a star, or an expanding stellar atmosphere can also produce Doppler broadening. See also line broadening.

Doppler broadening

[′däp·lər ‚brȯd·ən·iŋ]
(spectroscopy)
Frequency spreading that occurs in single-frequency radiation when the radiating atoms, molecules, or nuclei do not all have the same velocity and may each give rise to a different Doppler shift.
References in periodicals archive ?
There are several possible mechanisms of line broadening in plasma: self-absorption, pressure broadening, Doppler broadening, Stark broadening, etc.
Nemet and Kozma reported the broadening of transition lines as pressure, Stark, and Doppler broadening [19].
A chromate-inhibited primer has been characterized by Doppler broadening energy spectroscopy (DBES), scanning electron microscopy (SEM), and Raman spectroscopy.
Investigations into the uptake of water by primers have also been carried out using the positron-based techniques of positron annihilation lifetime spectroscopy (PALS) and Doppler broadening energy spectroscopy (DBES).
The design is certainly more elegant than the multiply redundant GIII reactors, and taking advantage of Doppler broadening is a sensible touch.
Could a failure of a misshaped pebble to reach operating temperature interfere with the vital Doppler broadening safety function?
Doppler broadening can be avoided if the transition is excited with two counter-propagating photons, as originally proposed by Bender et al.
The cyclic aging is performed on several samples at 26 kV with 8 h of power on and 16 h of power off for aging times of 6, 12 and 18 months and the samples were examined for defect characterization using both Doppler broadening and positron lifetime techniques.
5 Alloy using Positron Annihilation Doppler Broadening Technique
Doppler broadening positron annihilation (DBPAT) provides direct information about core and valance electrons in (CR-39) due to radiation effects.
Positron Annihilation Doppler Broadening Spectroscopy (PADBS) is a well established tool to characterize defects [7].
Doppler broadening positron annihilation technique (DBPAT) provides direct information about the change of core and valance electrons in Polyallyl diglycol carbonate (CR-39).