Optical Emission from O(1D) and O2(b 1Σg) in Ultraviolet Photolysis of O2 and CO2

The presence of O(1D) has been detected via 6300 Å emission in ultraviolet photolysis of O2 and CO2. Quenching rates for O(1D) and O2(1Σg) have been measured for O2, N2, CO2, and CO; we also find that quenching of O(1D) by O2 yields O2(1Σg) with nearly unit probability. The quenching rates compared well with those deduced from day airglow emission from the upper atmosphere; however we find a much smaller quenching rate by CO2 on O(1D) than have earlier workers using less direct methods. Photolysis of O2–CO mixtures leads to optical emission which exhibits a pronounced periodic variation in time. The quenching coefficients for O2, N2, CO2, and CO, in order, are as follows (cm3/sec): for O(1D), k1 = 6 × 10−11, k2 = 9 × 10−11, k3 = 3 × 10−12, k4 <5 × 10−11; for O2(1Σ)k5 = 1.5 × 10−16, k6 = 2 × 10−15, k7 = 3 × 10−13, k8 = 3 × 10−15.