Dissociative Excitation of Some Oxygen-Containing Molecules: Lifetimes and Electron-Impact Cross Sections

Decay lifetimes of seven vacuum-ultraviolet O I and O II emission multiplets have been measured using a pulsed electron beam in low-pressure samples of O₂, CO, NO, and H₂O. The lifetimes and cascade patterns of the lines are consistent with known autoionization processes. In two cases, spin-orbit-induced autoionization rates are determined. Absolute electron excitation functions for 8447--- O I have been measured in the above gases. Relative excitation functions for 1304- O I are normalized to the 8447- absolute cross section by means of a time-domain cascade analysis. A method for computing relative cross sections from N-exponential decays is outlined.