Algebraic approximation of the spectral line profile with accounting for strong and weak velocity-changing collisions
V.P. Kochanov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: line profile, weak collisions, strong collisions, approximation
Subsection: TOPICAL ISSUE
Abstract
The algebraic approximation of the spectral line profile derived with simultaneous account of small- and large-angle molecular scattering collisions was obtained. Deviations of the approximate line profile from the calculated exact profile do not exceed a tenth of a percent in the range of practically relevant parameters. It was shown that weak collisions with scattering on classical small angles diminish the collision line narrowing, which causes the profile to be flatter than the profile in the strong velocity-changing collisions model. The relative difference of the maximal amplitudes of these profiles can reach 15% that makes the accounting for weak collisions along with strong collisions to be necessary in a quantitative processing of high resolution inhomogeneously broadened spectra.
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