A cold cesium atomic beam produced out of a pyramidal funnel

We have built an atomic funnel which produces a slow and cold cesium atomic beam. The atomic funnel is based on a pyramidal Magneto Optical Trap (MOT) with a small hole at its apex. Characterization of the funnel operation has been carried out by fluorescence emission and absorption spectroscopy, and optical time of flight (TOF) methods. The atomic beam has a longitudinal velocity in the range 8–12 m/s and a spread less than 1.5 m/s. The transverse temperature is close to the Doppler limit. Typically, an atom flux 4×10⁹ atoms/s is attained. These features, combined with the compactness and simplicity of the experimental arrangement, make this system an ideal source for experiments in atom lithography and atom optics.