Production of a beam of highly vibrationally excited CO using perturbations.

An intense molecular beam of CO ( X 1 + ) in high vibrational states ( v = 17, 18) was produced by a new approach that we call PUMP – PUMP – PERTURB and DUMP . The basic idea is to access high vibrational states of CO e 3 − via a two-photon doubly resonant transition that is per- turbed by the A 1 state. DUMP -ing from this mixed (predominantly triplet) state allows access to high vibrational levels of CO ( X 1 + ). The success of the approach, which avoids the use of vacuum UV radiation in any of the excitation steps, is proven by laser induced fluorescence and resonance enhanced multi-photon ionization spectroscopy