Atom interferometry in an atomic fountain

An interferometer for atoms has been demonstrated using laser cooled sodium atoms and the mechanical effects of velocity sensitive stimulated Raman transitions. The interferometer has been used to measure the acceleration due to gravity, g, of an atom with a resolution of 3 parts in 10{dollar}sp8,{dollar} and interference has been observed for atomic wavepackets separated by as much as 6 mm.; Momentum recoil associated with velocity sensitive stimulated Raman transitions was used to coherently divide, redirect and recombine the atomic wavepacket. These transitions have also been used to prepare ensembles of atoms with one-dimensional velocity spreads as narrow as 300 {dollar}mu{dollar}m/sec, and to measure the temperature of polarization gradient cooled atoms.; Laser cooling and trapping techniques have been used to develop an "atomic fountain" source for the interferometer experiment: cold atoms were launched on vertical ballistic trajectories which turned due to gravity within the confines of the apparatus. This source has also been used in rf spectroscopy of the sodium groundstate hyperfine interval and for observation of the Casimir/van der Waals force between sodium atoms and a dielectric surface.