| Using atom interferometry, we have measured g, the local acceleration due to gravity, with a resolution of {dollar}Delta g/g = 2 times 10sp{lcub}-8{rcub}{dollar} after a single 1.3s measurement cycle, {dollar}2 times 10sp{lcub}-9{rcub}{dollar} after 1 minute and {dollar}1 times 10sp{lcub}-10{rcub}{dollar} after 2 days of integration time. The difference between our value for g and one obtained by a "falling corner-cube" optical interferometer is {dollar}(7 pm 7) times 10sp{lcub}-9{rcub}.{dollar} The beam splitters and mirrors of the atom interferometer are implemented using velocity sensitive stimulated Raman transitions and laser cooled cesium atoms in an atomic fountain are used as a well defined source of atoms.; We present experimental results, including the observation of tidal effects and a comparison with the "falling corner-cube" absolute gravimeter. We extend previous methods of analyzing the interferometer to include the effects of a gravitational gradient and finite length Raman pulses. We also present a detailed experimental and theoretical study of potential systematic errors and noise sources. |
