NIST caesium fountain frequency standard: preliminary results

The Time and Frequency Division of the National Institute of Standards and Technology (NIST) begun operation of a laser-cooled cesium atomic fountain for evaluation as a possible primary frequency standard. This device is conceptually similar to the Zacharias caesium fountain and is similar in layout to the BNM-LPTF (Observatoire de Paris) caesium fountain. This paper gives a brief description of the NIST Time and Frequency Division's caesium fountain and presents some preliminary data.