Open AccessCoherent Rayleigh-Brillouin scattering measurement of atmospheric atomic and molecular gas temperature
Author(s) -
J. S. Graul,
Taylor Lilly
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.020117
Subject(s) - rayleigh scattering , materials science , optics , argon , methane , scattering , brillouin scattering , fabry–pérot interferometer , boltzmann constant , spectrometer , atomic physics , arcjet rocket , line (geometry) , physics , chemistry , laser , thermodynamics , plasma , organic chemistry , quantum mechanics , geometry , mathematics
Broadband coherent Rayleigh-Brillouin scattering (CRBS) was used to measure translational gas temperatures for nitrogen, argon, and methane at the ambient pressure of 0.8 atm. Temperatures derived from spectral analysis were compared with experimentally-measured temperatures, with a maximum 5.2% difference for all gases at all temperatures; and with nitrogen, argon, and methane exhibiting average differences over the temperature range tested of 0.8%, 1.4% and -0.5%, respectively. These values are consistent with the 2% estimated, experimental error of the experiment. Improving upon the efficiency of previous line shape acquisition methods, CRBS data were spectrally de-convolved using a cost effective, purpose-designed, Fabry-Perot etalon spectrometer. The resulting line shapes were compared to models obtained from approximations to the 1D Boltzmann equation. Although this study employed broadband CRBS for explicit gas temperature measurement, similar line shape acquisition techniques could be used with broadband coherent Rayleigh scattering (CRS) to experimentally-measure gas temperatures, pressures and other transport properties in both the kinetic (CRBS) and rarefied (CRS) regimes.