Vibrational excitation of CO molecules by infrared free electron laser

• Published in: Journal of electron spectroscopy and related phenomena Vol. 128; no. 1; pp. 67 - 73
• Main Authors: Ogi, Y, Endo, T, Tsukiyama, K, Kondoh, H, Tono, K, Ogawa, Y, Hamada, Y, Ohta, T, Kuroda, H
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2003
• Subjects: Free electron laser; REMPI; Vibrational excitation; Vibrational excitation; Free electron laser; CO; REMPI
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/S0368-2048(02)00211-6

This paper describes the vibrational excitation of CO molecules by FEL-SUT (Free Electron Laser at Tokyo University of Science). FEL is tuned to 4.67 μm, corresponding to the X 1Σ +( v″=1)←( v″=0) transition of CO. The population of the vibrationally excited states is probed by the (2+1) resonance enhanced multiphoton ionization technique via the B 1Σ + Rydberg state. We find that ∼10% of the population in v″=0 is excited to v″=1. In spite of the existence of the resonant vibrational ladder climbing channels via specific rotational levels, no signal originating from v″=2 is detectable. The predissociation in the B 1Σ +( v′=2) state is believed to be responsible for the absence of CO + signals.