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NIST Cesium Fountains – Current Status and Future Prospects

Published

Author(s)

Steven R. Jefferts, Thomas P. Heavner, Thomas E. Parker, Jon H. Shirley

Abstract

We review the current status of the U.S. Primary Frequency Standard, NIST-F1. NIST-F1 is a laser-cooled cesium fountain based frequency standard with an inaccuracy of less than δ f/f {less than or equal to} 5×10-16 limited mainly by the radiation field in the room-temperature fountain (blackbody shift). NIST-F1 is one of the best cesium fountain currently contributing to international atomic time, but has reached a point that it is impractical to improve its accuracy substantially. Therefore we are building a new fountain, imaginatively named NIST-F2, with a cryogenic (77K) Ramsey interrogation zone which lowers the blackbody shift by several orders of magnitude. NIST-F2 is currently undergoing final assembly and we will discuss our planned (hoped for) performance which includes frequency inaccuracy of δ f/f {less than} 1×10^-16^.
Citation
Proceedings of the SPIE: Time and Frequency Metrology
Volume
6673
Issue
667309

Keywords

atomic clock, cesium clock, primary frequency standard

Citation

Jefferts, S. , Heavner, T. , Parker, T. and Shirley, J. (2007), NIST Cesium Fountains – Current Status and Future Prospects, Proceedings of the SPIE: Time and Frequency Metrology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50590 (Accessed June 25, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created September 12, 2007, Updated February 17, 2017