Characterization of a cold cesium source for PARCS: Primary Atomic Reference Clock in Space

The PARCS (Primary Atomic Reference Clock in Space) project is a joint NIST JPL venture aimed at placing a Cs atomic clock aboard the International Space Station. This orbiting clock will achieve high accuracies in part due to the long Ramsey times afforded by the microgravity environment. The clock will allow a wide range of precision tests of fundamental physics including relativity theory. Our group at NIST is performing experimental studies of a "prototype" cold Cs source based on launching atoms from optical molasses. The results of our work will be applied to the design and construction of a robust, space qualified device. Additionally, this work is important for the development of future Cs fountains. We describe our apparatus, the present state of our experimental work, and planned improvements.