Knowledge Bank

We have obtained spectra of individual rotation-vibration lines in the tentatively identified $5\nu 1$ band of ammonia near 6450 {\AA} from pressures of 20 to 380 Torr, and the tentatively identified $5\nu 1+\nu 3$ band of $CH4$ at $6190$ {\AA} from pressures of 80 to 1200 Torr. We utilized a resonant photoacoustic detection cell placed inside the cavity of a tunable dye laser mechanically chopped at approximately 2500 Hz. The application of such measurements to the study of planetary atmospheres and use of these transitions in selective photo-excitation will be discussed.