Characterization of the USNO cesium fountain

We have performed an initial characterization of the stability of the U.S. Naval Observatory (USNO) cesium fountain atomic clock. This device has a short-term fractional frequency stability of up to 1.5/spl times/10/sup -13/ /spl tau/-/sup 1/2/. This short-term performance enables us to measure hydrogen maser behavior over the short to medium term. We have recently implemented real time steering of a hydrogen maser with the fountain. Over a period of roughly 9 days of continuous operation, we have steered out the drift of a cavity tuned maser.