Improvements on the FANTASIO set-up and new spectroscopic results concerning the Ar-H2O van der Waals complex in the 2OH overtone region

Bogomolov, Alexandr [UCL] Glorieux, Robin [UCL] Herman, Michel Corbo, Thomas [UCL] Collignon, Simon [UCL] Hays, Brian [UCL] Lederer, Dimitri Moazzen-Ahmadi, Nasser Libert, Alexis [UCL] Tomasetti, Benjamin [UCL] Fréreux, Joffrey [UCL] Lauzin, Clément [UCL] et al.[show all]

We present a series of improvements of the FANTASIO experimental set-up that couples a supersonic expansion to a cavity ring-down spectrometer originally reported by M. Herman, et al., Mol. Phys. 105, 815 (2007). In particular, the implementation of a new pulsed slit valve of 80 mm in length is detailed. The design is based on a powerful piezo stack actuator. Schlieren imaging is used to verify the homogeneity of the molecular beam and the quality of the pulsed slit performance. The ability to form weakly bound van der Waals complexes is assessed using the cavity ring-down spectrometer and a new chirped-pulse Fourier transform microwave spectrometer with the 12-18 GHz operating range. The water hexamer and heptamer were observed using this microwave spectrometer. Following enhancements and an extended laser