REMPI-TOF studies of the HF dimer

Resonance-enhanced multiphoton ionisation and time-of-flight mass spectra analysis of jet-cooled HF–argon mixtures are presented. Two-photon resonance transitions in the HF dimer, (HF)2, are observed for the first time. Simulation calculations reveal transitions to a Rydberg state and allow determination of energy parameters for the excited state dimer. The process of excitation is discussed.