Time-, angle- and kinetic-energy-resolved photoelectron spectroscopy of highly excited states of NO

We investigate non-adiabatic dynamics of NO molecules that are photo-excited in the vacuum ultraviolet photon energy range using time-resolved velocity map imaging. Highly excited valence and Rydberg states are populated with a tunable (147-151 nm) femtosecond laser pulse and then ionized by a time-delayed near-IR laser pulse. Three main contributions are observed in the photoelectron kinetic spectra with corresponding electron yields that show pronounced oscillations. Two oscillations are assigned to ro-vibronic coupling in the valence-Rydberg mixture of the B-'2 Delta (v = 7) and 4d delta N-2 Delta (v = 0) states and the B-2 Pi (v = 25) and 4p pi K-2 Pi (v = 1) states, respectively. We assign a third oscillation to originate from a coupling between two Rydberg states.