NIST Primary Frequency Standards and the Realization of the SI Second

@article{Lombardi2007NISTPF,
  title={NIST Primary Frequency Standards and the Realization of the SI Second},
  author={Michael A. Lombardi and Thomas P. Heavner and Steven R. Jefferts},
  journal={NCSLI Measure},
  year={2007},
  volume={2},
  pages={74 - 89}
}
Abstract: As the base unit of time interval, the second holds a place of preeminence in the world of metrology. Time interval, and its reciprocal, frequency, can be measured with more resolution and less uncertainty than any of the other physical quantities. The precise realization of the second was made possible by the development of frequency standards based on the energy transitions of atoms, an event that not only revolutionized the science of timekeeping, but also forever changed many… 

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References

SHOWING 1-10 OF 84 REFERENCES

The metrology of time

  • E. F. Arias
  • Physics
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2005
TLDR
The evolution of the measuring of time, current state-of-the-art measures and future challenges are explained.

Standards of Time and Frequency at the Outset of the 21st Century

After 50 years of development, microwave atomic clocks based on cesium have achieved fractional uncertainties below 1 part in 1015, a level unequaled in all of metrology. The past 5 years have seen

The Measurement of Time: Time, Frequency and the Atomic Clock

This book provides an in-depth and comprehensive survey of the current state-of-the-art of the international atomic timescale and its underpinning relationship to practical and legal timescales. The

Improvements in Atomic Cesium Beam Frequency Standards at the National Bureau of Standards

The National Bureau of Standards Frequency Standard, NBS-III, a cesium beam with a 3.66-meter interaction region, has been in operation since 1963. The last published (1966) accuracy capability for

Time and frequency measurement at NIST: the first 100 years

  • D. Sullivan
  • Physics
    Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)
  • 2001
During this, the NIST Centennial Year, I look back on the first 100 years and summarize NIST work on time and frequency measurement, a topic of some prominence from the early years of the

The Performance and Capability of Cesium Beam Frequency Standards at the National Bureau of Standards

NBS II, the older of the two cesium atomic beam frequency standards which are used alternatively as the United States Frequency Standard, has been operating for more than five years. The contribution

Operation of the NIST-F1 caesium fountain primary frequency standard with a maser ensemble, including the impact of frequency transfer noise

The operation of a caesium fountain primary frequency standard is greatly influenced by the characteristics of two other important facilities. The first is a stable frequency reference and the second

Cesium Primary Frequency References

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

Accuracy Evaluation and Stability of the NBS Primary Frequency Standards

The National Bureau of Standards has two primary standards for frequency and the unit of time. They are both cesium devices and are designated NBS-4 and NBS-5. The design of NBS-5 is discussed in

NIST-F1: recent improvements and accuracy evaluations

In the last several years we have made many improvements to NIST-F1 (a laser-cooled Cs fountain primary frequency standard at the National Institute of Standards and Technology (NIST) in Boulder,
...