Spectroscopy in ortho-H2O enriched molecular beam

This setup enables to separate nuclear spin isomers of water in a supersonic molecular beam using a magnetic focalisation technique.The continuous molecular beam is produced from the supersonic expansion of water vapour seeded in argon carrier gas. Ce center of the jet is collected using a skimmer to enter the delection zone after two stages if differential pumping. Water molecules in the ortho nuclear spin state (I=1) interact with a strong magnetic gradient produced by a serie of hexapolar magnets enabling the focalisation of the molecules having MI=-1 sublevel, when molecules having MI=+1 are deflected and molecules in the sublevel MI=0, that is ortho and para states, do not change trajectories.The characterisation of this ortho-enriched molecular beam is directly done in the molecular beam using REMPI (2+1) spectroscopy coupled with a time-of-flight mass spectrometer.

A few photos illustrating our setup: