Oxygen and other atmospheric gases

Laser multiphoton, mass, and photoelectron spectroscopy was used to investigate the energy level structure and photophysics of oxygen and other atmospheric gases. Particular emphasis was placed on determining the location, predissociation and photoionization processes of the previously unknown lower ns and nd gerade Rydberg states and their interactions with valence states. A shape resonance in the ionization continuum near threshold was found to play a large role in inducing non-Franck-Condon transitions. Optimum transitions for production of vibrationally state-selected O2+ ions were found. The effects of dissociation continua and strongly mixed Rydberg-valence states as intermediates in multiphoton processes were demonstrated and explored.