INFRARED EMISSION SPECTRA OF $^{13} C$ $^{16} O$ AND $^{12}$C$^{18}$O

Abstract

Author Institution: Department of Physics, The Pennsylvania State UniversityThe infrared emission spectra at 4.5 $\mu m$ of $^{13}$C$^{16} O$ and $^{12}C_{18_{0}}$ have been measured at high resolution. The v $\rightarrow$ v - 1 sequence from v = 1 to v = 11 in $^{13}$C$^{16} O$ was recorded (next to the $^{13}CO_{2}$ emission) using a small amount (150 mg) of 90\%-enriched $^{13}CO_{2}$ mined with He and $N_{2}$ in a d.c.-discharge in a slow-flowing system. The 1-0, 2-1, and 3-2 bands of $^{12}$C$^{18} O$ were detected in natural abundance in a CO-He discharge thanks to the high working resolution (0.015 - $0.020 cm^{-1}$, of our new 4.5 to vacuum spectrometer with a 40 cm, 31.6 lines/mm grating. The data were combined with recent laser heterodyne measurements to calculate a set of Dunham coefficients for the two isotopic molecules