Measurements of air-, N(2)-, and O(2) -broadened halfwidths and pressure-induced line shifts in the v(3) band of (13)CH(4).
Air-, nitrogen-, and oxygen-broadened halfwidth and pressure-induced line shift coefficients have been measured for over seventy-five individual vibration-rotation transitions in the v(3) fundamental band of (13)CH(4)at 3 mum from room temperature IR laboratory absorption spectra recorded at a 0.01-cm(-1) resolution with a Fourier transform spectrometer. Transitions up to J" = 13 in the P-branch and J" = 7 in the R-branch were analyzed using a nonlinear least-squares curve fitting technique assuming a Voigt line shape. From the analysis, we have determined the mean ratios of air- to nitrogen-broadened and air- to oxygen-broadened halfwidth coefficients obtained for the same transitions as 1.00 +/- 0.03 and 1.06 +/- 0.04, respectively. The measured pressure shift coefficients were predominantly negative, and the mean and standard deviation values for air-, nitrogen-, and oxygen-broadened shifts were -0.0067 +/- 0.0032, -0.0068 +/- 0.0041, and -0.0066 +/- 0.0028 cm(-1) atm(-1), respectively. Comparisons are made with the results obtained for similar transitions in the v(3) band of (12)CH(4) and the v(4) band of (13)CH(4).
Devi
V M
VM
Benner
D C
DC
Smith
M A
MA
Rinsland
C P
CP