Toward an atom laser: Cold atoms in a long, high-gradient magnetic guide

The propagation of an atomic beam through a 1.7 in long magnetic guide with magnetic field gradient of up to 2.7 kGauss-cm-1 has been demonstrated. The guide is side-loaded with an atomic beam from a Pyramidal MOT Low-velocity Intense Source. The atomic beam observed at the end of the guide has a flux of 3x107 atoms-s-1 with a velocity of 1.2mn/s, a transverse temperature of 420+/-40 muK and a longitudinal temperature of 1 mK. The guided atomic beam was mode-filtered by selective removal of high-energy atoms using radio-frequency coupling to magnetically un-trapped states. We found that the phase-space density of the atomic beam was very low for evaporative cooling to be functional.;An imaging technique was developed to characterize the guided atomic flow in the presence of a high magnetic field gradient. This technique utilizes the open-channel transition to obtain nearly constant photon yield per atom independent of the location of the atone in the guide, providing a mapping of the fluorescence images to the atomic-density profiles. This technique was theoretically studied using Quantum Monte-Carlo Simulations and validated.;A Zeeman slower was constructed and characterized to be used as the primary source of atoms to the magnetic guide. The Zeeman slower output atomic beam has a flux of 3x1011 atoms-s-1 at a velocity of 40 m/s. We have designed a new injection scheme to transfer atoms from the Zeeman slower to the magnetic guide efficiently. The details of a new method to evaporatively cool atoms in the magnetic guide using surface adsorption are described. Finally, a new guide geometry based on a spiral structure is discussed.