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Title: Competition of Short-Range and Long-Range Mechanisms of Spectral Line Broadening in Emission of Atomic and Molecular Gases

Abstract

An analogy is shown for broadening the spectral line of atoms in the case of competition between the short-range Doppler broadening mechanism and the long-range impact mechanism in atomic gases, as well as for the absorption band of a molecular gas in the infrared (IR) region of the spectrum, where the longrange part of the spectrum is also determined by the impact mechanism of the broadening. The long-range part in the pedestal region of the absorption band is associated with the distribution of molecules over the rotational states, and, in the range of wings of the absorption band, it is due to a finite time of collisions between emitting and perturbed molecules. The flux of resonant radiation produced by an excited atomic gas is estimated using the concepts of the spectral absorption band and a large optical thickness of the gas. These concepts are used for a molecular gas where, in the framework of the regular model (the Elsasser model), expressions are given for the absorption coefficient related to a specific spectral absorption band, separately in the pedestal region and for wings of the absorption band. As a demonstration of the possibilities of these concepts, the IR flux is calculatedmore » on the surface of Venus from its atmosphere, which includes seven vibrational transitions of the carbon dioxide molecule and amounts to 26% of the total flux of IR radiation emitted by the Venus surface. An analysis of the Venus energy balance leads to the conclusion that the main part of IR radiation of the Venus atmosphere falling on its surface is formed by a microscopic dust in the Venus atmosphere. This channel of the Venus energy balance is realized if the mass of a microscopic dust in the Venus atmosphere is seven orders of magnitude less than the mass of atmospheric carbon dioxide.« less

Authors:
 [1]
  1. Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)
Publication Date:
OSTI Identifier:
22749793
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 127; Journal Issue: 1; Other Information: Copyright (c) 2018 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ATMOSPHERES; ATOMS; CARBON DIOXIDE; COMPETITION; DOPPLER BROADENING; ENERGY BALANCE; GASES; INFRARED RADIATION; MOLECULES; REST MASS; ROTATIONAL STATES; VENUS PLANET

Citation Formats

Smirnov, B. M., E-mail: bmsmirnov@gmail.com. Competition of Short-Range and Long-Range Mechanisms of Spectral Line Broadening in Emission of Atomic and Molecular Gases. United States: N. p., 2018. Web. doi:10.1134/S1063776118070117.
Smirnov, B. M., E-mail: bmsmirnov@gmail.com. Competition of Short-Range and Long-Range Mechanisms of Spectral Line Broadening in Emission of Atomic and Molecular Gases. United States. doi:10.1134/S1063776118070117.
Smirnov, B. M., E-mail: bmsmirnov@gmail.com. Sun . "Competition of Short-Range and Long-Range Mechanisms of Spectral Line Broadening in Emission of Atomic and Molecular Gases". United States. doi:10.1134/S1063776118070117.
@article{osti_22749793,
title = {Competition of Short-Range and Long-Range Mechanisms of Spectral Line Broadening in Emission of Atomic and Molecular Gases},
author = {Smirnov, B. M., E-mail: bmsmirnov@gmail.com},
abstractNote = {An analogy is shown for broadening the spectral line of atoms in the case of competition between the short-range Doppler broadening mechanism and the long-range impact mechanism in atomic gases, as well as for the absorption band of a molecular gas in the infrared (IR) region of the spectrum, where the longrange part of the spectrum is also determined by the impact mechanism of the broadening. The long-range part in the pedestal region of the absorption band is associated with the distribution of molecules over the rotational states, and, in the range of wings of the absorption band, it is due to a finite time of collisions between emitting and perturbed molecules. The flux of resonant radiation produced by an excited atomic gas is estimated using the concepts of the spectral absorption band and a large optical thickness of the gas. These concepts are used for a molecular gas where, in the framework of the regular model (the Elsasser model), expressions are given for the absorption coefficient related to a specific spectral absorption band, separately in the pedestal region and for wings of the absorption band. As a demonstration of the possibilities of these concepts, the IR flux is calculated on the surface of Venus from its atmosphere, which includes seven vibrational transitions of the carbon dioxide molecule and amounts to 26% of the total flux of IR radiation emitted by the Venus surface. An analysis of the Venus energy balance leads to the conclusion that the main part of IR radiation of the Venus atmosphere falling on its surface is formed by a microscopic dust in the Venus atmosphere. This channel of the Venus energy balance is realized if the mass of a microscopic dust in the Venus atmosphere is seven orders of magnitude less than the mass of atmospheric carbon dioxide.},
doi = {10.1134/S1063776118070117},
journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 1,
volume = 127,
place = {United States},
year = {2018},
month = {7}
}