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Search Publications by: Tom Heavner ()

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Displaying 76 - 100 of 178

Cesium Primary Frequency References

February 1, 2007
Author(s)
Steven R. Jefferts, Thomas P. Heavner, Elizabeth A. Donley
Primary frequency standards with stated inaccuracies of δf/f ~ 10 15 or slightly better are in use today in several national timing laboratories. These standards, which are the most accurate in the world today, use laser-cooled cesium atoms to obtain this

A single-atom optical clock with high accuracy

July 14, 2006
Author(s)
Windell Oskay, Scott A. Diddams, Elizabeth A. Donley, Tara M. Fortier, Thomas P. Heavner, Leo W. Hollberg, Wayne M. Itano, Steven R. Jefferts, M J. Jensen, Kyoungsik Kim, F Levi, Thomas E. Parker, James C. Bergquist
For the past fifty years, atomic frequency standards based on the cesium ground-state hyperfine splitting have been the most accurate timepieces in the world. One of the most accurate, current-generation, cesium standards is the NIST-F1 fountain, which has

Absolute Optical Frequency Measurements with a Fractional Uncertainty at 1 x 10 -15

June 5, 2006
Author(s)
Jason Stalnaker, Scott A. Diddams, Leo W. Hollberg, Kyoungsik Kim, Elizabeth A. Donley, Thomas P. Heavner, Steven R. Jefferts, Filippo Levi, Thomas E. Parker, James C. Bergquist, Wayne M. Itano, Marie J. Jensen, Luca Lorini, Windell Oskay, Tara M. Fortier, J Torgerson
We report the technical details specific to our recent measurements of the optical frequency of the mercury single-ion clock in terms of the SI second as realized by the NIST-F1 cesium fountain clock. In these measurements the total fractional uncertainty

Power Dependence of the Shift Caused by Spurious Spectral Components in Atomic Fountain

March 27, 2006
Author(s)
Filippo Levi, Jon H. Shirley, Thomas P. Heavner, Dai Yu, Steven R. Jefferts
In this paper we analyze the behavior of the frequency shift caused by spurious spectral component in the microwave spectrum against variation of the excitation microwave field. The theory of the shift caused by the presence of spurs in the microwave

PARCS: NASAs Laser-Cooled Atomic clock in Space

December 1, 2005
Author(s)
Donald Sullivan, Neil Ashby, Elizabeth A. Donley, Thomas P. Heavner, Leo W. Hollberg, Steven R. Jefferts, William Klipstein, David Seidel, D. J. Phillips
The PARCS (Primary Atomic Reference Clock in Space) mission is designed, not only to perform certain tests of relativity theory, but also to demonstrate space-clock technology that may prove useful as an international standard of frequency and time and for
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