Development of a miniature laser-cooled Cs fountain frequency standard at NIST

We are developing a small laser-cooled Cs fountain at NIST with the goal of achieving exceptional short-term stability of /spl sigma//sub y/(/spl tau/)/spl ap/2/spl times/10/sup -14//spl tau//sup -1/2/ with a long-term stability of /spl ap/10/sup -15/. Although this device is not designed to achieve the accuracy of the NIST primary frequency standard NIST-F1, this small, portable system will prove valuable as a local oscillator with intermediate accuracy. We discuss the performance goals of this frequency standard, the design philosophy, the existing physics package, and future directions.