TIME-RESOLVED MULTIPHOTON IONIZATION STUDY OF THE 102 NM STATE OF NO

We have used subpicosecond deep UV laser pulses (near 205 nm) in a tim e-resolved (2+1) multiphoton ionization study of the two-photon state of NO at 102 nm via a one-photon resonance with the A (2) Sigma(+) (3s sigma) (v=2) state. The two-photon excited state lifetime exhibits a strong pressure dependence from which the collisionless lifetime and t he bimolecular depopulation or quenching rate constant were obtained. The large quenching rate constant strongly suggests that the state is a medium (10-12) n Rydberg level in the series converging to the groun d electronic state of NO+. The subnanosecond collisionless lifetime im plies that this state is subject to predissociation and/or autoionizat ion.