Generation of UTC(PTB) as a fountain-clock based time scale

Bauch, A.; Weyers, S.; Piester, D.; Staliuniene, Egle; Yang, Wensheng

doi:10.1088/0026-1394/49/3/180

Cited by 96 publications

(57 citation statements)

References 16 publications

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“…A real‐world Cs‐fountain time scale, such as UTC(OP) and UTC(PTB), has quite similar performance to the red curve in Figure . For example, analyzing the UTC(OP) data during Modified Julian Date (MJD) 56649 – 57514 indicates that the frequency stability of UTC(OP) is about 4.8 × 10 −16 at 10 days and 2.4 × 10 −16 at 60 days.…”

Section: Simulation Resultsmentioning

confidence: 86%

“…The continuously operating cesium fountain is simulated by white frequency noise with a fractional frequency stability of 1.4 × 10 −15 at 1 day, which is typical Cs fountain performance at low atom density. [4][5][6] We simulate an optical clock as having white frequency noise with fractional frequency stability of 3.4 × 10 −16 at 1 second, which is typical for the Sr/Yb optical-lattice clock. 2,3 The simulated optical-clock data are truncated to match various operational schedules as discussed below.…”

Section: Clock Simulationmentioning

confidence: 99%

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Progress on optical-clock-based time scale at NIST: Simulations and preliminary real-data analysis

et al. 2018

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This paper describes the recent National Institute of Standards and Technology (NIST) work on incorporating an optical clock into a time scale. We simulate a time scale composed of continuously operating commercial hydrogen masers and an optical frequency standard that does not operate continuously as a clock. The simulations indicate that to achieve the same performance of a continuously operating Cs‐fountain time scale, it is necessary to run an optical frequency standard 12 minutes per half a day, or 1 hour per day, or 4 hours per 2.33 day, or 12 hours per week. Following the simulations, a Yb optical clock at NIST was frequently operated during the periods of 2017 March – April and 2017 late October – late December. During this operation, comb‐mediated measurements between the Yb clock and a hydrogen maser had durations ranging from a few minutes to a few hours, depending on the experimental arrangements. This paper analyzes these real data preliminarily and discusses the results. More data are needed to make a more complete assessment.

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Section: Simulation Resultsmentioning

confidence: 86%

Section: Clock Simulationmentioning

confidence: 99%

Progress on optical-clock-based time scale at NIST: Simulations and preliminary real-data analysis

et al. 2018

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“…The PTB was the first laboratory to do so since February 2010, [43] where the Cs primary fountain is used both for its short-term stability and as a reference to extrapolate the rate of UTC(PTB) with respect to TAI. The PTB was the first laboratory to do so since February 2010, [43] where the Cs primary fountain is used both for its short-term stability and as a reference to extrapolate the rate of UTC(PTB) with respect to TAI.…”

Section: Fountain-driven Timescalesmentioning

confidence: 99%

The Hyperfine Transition for the Definition of the Second

Arias

Petit

2019

Annalen der Physik

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The unit of time of the International System of Units (SI), the "atomic second" was defined through a constant of physics in 1967. It is derived from the frequency of the hyperfine transition of the atom of cesium 133. From the astronomical definition of the second until today, the accuracy of the realization of the second has improved by eight orders of magnitude, with a rate that has increased since the development of the cesium frequency standards, to reach parts in 10 16 for the best clocks today. In 2018, when the new SI was adopted, the time metrology community proved that a new generation of frequency standards operating in optical wavelengths has uncertainties at the level of 10 -18 , and challenge the implementation of high accurate frequency and time comparison techniques to decide on a revision of the definition of the second. Herein, the progress in the definition and realization of the second from astronomy until today is reviewed, an inventory of the present resources is assembled and a brief view for the future given.

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“…La courbe montre une amélioration de plus d'un ordre de grandeur du nouvel UTC(OP), mis en place à partir du MJD 56229, par rapport au système précédent basé sur une horloge commerciale à jet thermique de cé-sium. La figure 6 présente cette comparaison, depuis la mise en place du nouvel UTC(OP) en octobre 2012, ainsi que les performances de deux autres UTC(k) fondés éga-lement sur l'exploitation de fontaines atomiques [15][16][17]. Sur les trois dernières années, UTC(OP) s'est maintenu à mieux que 10 ns de l'UTC, avec une valeur moyenne de 0,33 ns, et un écart type de 2,1 ns.…”

Section: Nouvelle Chaîne De Distribution De Utc(op)unclassified