Two-dimensional imaging of metastable CO molecules

Abstract

Direct time and spatially resolved detection of metastable CO molecules, prepared in selected quantum states via pulsed laser excitation, is experimentally demonstrated in a molecular beam machine. Characterization of the molecular beam in terms of parallel and perpendicular velocity distributions and rotational temperatures is performed. A direct two‐dimensional (2D) demonstration of the mass‐focusing effect in binary gas mixtures is given. Two‐dimensional imaging of the spatial distribution of the metastable a 3Π CO molecules in the beam after passage through a hexapole field is used to study hexapole focusing performance. Structured 2D images demonstrate the dependence of the focusing characteristics on the magnitude of the Λ‐doubling and on the angular dependence of the focusing force in a hexapole consisting of cylindrical rods.