Collisional Removal of by O(3P)

The rate coefficient for collisional removal of O 2 ( b 1 Σ g + , υ = 1 ) by O(3P), kO, is an essential parameter in modeling the emissions from O 2 ( b 1 Σ g + , υ = 1 ) in the Earth’s thermosphere. We report a laboratory measurement of this rate coefficient at room temperature. A fluorine laser is used to photodissociate O2 at 157.6 nm, followed by detection of the time-resolved fluorescence from subsequently generated O 2 ( b 1 Σ g + , υ = 1 ) . The determined value is k O = 4.5 - 1.3 + 0.8 × 10 - 12 cm 3 s - 1 ( 2 σ ) . The rate coefficient for collisional removal of O 2 ( b 1 Σ g + , υ = 1 ) by O2 is also determined, with a value of (1.5 ± 0.1) × 10−11 cm3 s−1.