Initial study of the distributed cavity phase shift for the new microwave cavities of NIST F1

Published

December 21, 2021

Author(s)

Gregory Hoth, Bijunath Patla, Neil Ashby, Vladislav Gerginov

Abstract

We are in the process of re-evaluating NIST-F1, the cesium fountain primary frequency standard at the National Institute of Standards and Technology (NIST). Here, we describe an initial study of the frequency bias caused by the distributed cavity phase (DCP) in NIST-F1 using the techniques developed by Li and Gibble [Li and Gibble, Metrologia 41 (2004), Li and Gibble Metrologia 47 (2010)]. We solve for the field distribution in the microwave cavity of NIST-F1 using a 3D finite element model. Then, a density matrix solver is used to simulate the cold atoms' interaction with the cavity field. By averaging over many atomic trajectories, we estimate the DCP frequency bias for NIST-F1 is less than 2 × 10^(-16) at the typical operating power if the atomic cloud is centered on the fountain axis.

Proceedings Title

Proceedings of the 2022 Joint conference of the European Frequency and Time Forum & the IEEE International Frequency Control Symposium

Conference Dates

April 25-28, 2022

Conference Location

Paris, FR

Conference Title

2022 Joint conference of the European Frequency and Time Forum & the IEEE International Frequency Control Symposium

Pub Type

Conferences

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Keywords

Cesium fountain clock, distributed cavity phase shift, finite element modeling, frequency bias

Citation

Hoth, G. , Patla, B. , Ashby, N. and Gerginov, V. (2021), Initial study of the distributed cavity phase shift for the new microwave cavities of NIST F1, Proceedings of the 2022 Joint conference of the European Frequency and Time Forum & the IEEE International Frequency Control Symposium, Paris, FR, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933906 (Accessed October 9, 2025)