Direct Measurements of Lifetimes of Low-lying Excited Electronic States in Nitric Oxide

Lifetimes of 32 bands in NO originating from the A 2 Σ + , B 2 Π, B ' 2 Δ and D 2 Σ + states and a system reported by Migeotte have been directly measured, using the high frequency deflection technique. The results are compared to earlier direct measurements and the lifetimes are discussed in relation to various types of states. For instance the Migeotte bands are found to have lifetimes similar to those of the D 2 Σ + state, and consequently they are likely to originate from this (Rydberg) state. The lifetime of the C 2 Π state is also discussed with particular application to the NO concentration in the atmosphere.