# Comment on "first accuracy evaluation of NIST-F2"

@article{Gibble2015CommentO, title={Comment on "first accuracy evaluation of NIST-F2"}, author={K. Gibble}, journal={Metrologia}, year={2015}, volume={52}, pages={163-166} }

We discuss the treatment of the systematic frequency shifts due to microwave lensing and distributed cavity phase in Heavner et al 2014 Metrologia 51 174–82. We explain that the microwave lensing frequency shift is generally non-zero and finite in the limit of no applied microwave field. This systematic error was incorrectly treated and we find that it contributes a significant frequency offset. Accounting for this shift implies that the measured microwave amplitude dependence (e.g. due to… Expand

#### 6 Citations

Measurement of the Microwave Lensing shift in NIST-F1 and NIST-F2

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With several Primary Frequency Standards (PFS) across the world demonstrating systematic fractional frequency uncertainties on order of 1 x 10-16, it is crucial to accurately measure or model even… Expand

Reply to ``Comment on `Ramsey spectroscopy, matter-wave interferometry, and the microwave-lensing frequency shift' ''

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The Comment by Jefferts et al. [Phys. Rev. A 91, 067601 (2015)] discusses the microwave-lensing frequency shift’s possible dependence on the initial wave-packet size and two effects of wall… Expand

Microwave lensing frequency shift of the PHARAO laser-cooled microgravity atomic clock

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We evaluate the microwave lensing frequency shift of the microgravity laser-cooled caesium clock PHARAO. We find microwave lensing frequency shifts of δν/ν = 11 × 10−17 to 13 × 10−17, larger than the… Expand

Systematic Effects in Atomic Fountain Clocks

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We describe recent advances in the accuracies of atomic fountain clocks. New rigorous treatments of the previously large systematic uncertainties, distributed cavity phase, microwave lensing, and… Expand

Advances in the accuracy, stability, and reliability of the PTB primary fountain clocks.

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Improvements of the systematic uncertainty, frequency instability, and long-term reliability of the two caesium fountain primary frequency standards CSF1 and CSF2 at PTB (Physikalisch-Technische… Expand

Qualification and frequency accuracy of the space-based primary frequency standard PHARAO

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The flight model of the laser cooled cesium atomic clock, PHARAO, has been qualified for operation in space. The clock has passed the vibration, thermal and electromagnetic compatibility tests… Expand

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