Thèse de doctorat : Université de Neuchâtel, 2017.
This work focusses on the study and the metrological evaluation of the FoCS-2 primary frequency standard. This atomic clock, one of a kind, uses a continuous beam of cold cesium atoms. Following 20 years of development in the Observatory of Neuchâtel and the Time and Frequency Laboratory of the University of Neuchâtel, FoCS-2 is now located in the federal institute of metrology METAS in Bern....
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In: Journal of Physics: Conference Series, 2016, vol. 723, no. 1, p. 012010
The continuous cesium fountain clock FoCS-2 at METAS presents many unique characteristics and challenges in comparison with standard pulsed fountain clocks. For several years FoCS-2 was limited by an unexplained frequency sensitivity on the velocity of the atoms, in the range of 140 · 10-15. Recent experiments allowed us to identify the origin of this problem as undesirable microwave...
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In: Metrologia, 2017, vol. 54, no. 2, p. 239-246
We report the evaluation of the second-order Zeeman shift in the continuous atomic fountain clock FoCS-2. Because of its continuous operation and geometrical constraints, the methods used in pulsed fountains are not applicable. We use here time-resolved Zeeman spectroscopy to probe the magnetic field profile in the clock. Pulses of ac magnetic excitation allow us to spatially resolve the Zeeman...
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