Diode laser absorption spectroscopy measurement of linestrengths and pressure broadening coefficients of the methane 2ν3 band at elevated temperatures

Abstract A diode laser sensor based on absorption spectroscopy has been developed for the measurement of spectroscopic parameters in the R  (3) and R  (4) manifolds of 2 ν 3 band of CH 4 . Individual linestrengths of each transition are determined for a range of temperatures. In addition, collision-broadened half-widths for CO 2 , N 2 , H 2 O, CH 4 , and CO collision partners are measured as a function of temperature and pressure for these strongly overlapped transitions. From this, temperature dependence of the collision half-width for each collision partner is determined. Using a new method for calculation of collisional broadening at high temperatures for strongly overlapped transitions makes these transitions accessible for spectroscopy.

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