Evaluation of the METAS-FoCS-2 primary frequency standard
|Directeur /trice||Pr Thomas Südmeyer|
|Résumé de la thèse||
The main goal of this work is to study some metrological aspects that are specific to the cold cesium continuous fountain (FOCs 2) developed at the LTF (Laboratoire Temps Fréquence // Time and Frequency Laboratory) of Neuchâtel in collaboration with the Swiss Institute of Metrology (METAS) in Bern.
This frequency standard is based on a continuous beam of cold and slow
cesium atoms. In comparison with the pulsed fountains, the continuous operation
of the fountain bears several advantages. As a consequence of the low atomic density and higher beam temperatures, the shift of the atomic resonance frequency due to the collisions between cold atoms is strongly reduced and becomes negligible. A second advantage is the suppression of the degradation of the frequency stability due to the phase noise of the local oscillator. The frequency stability is therefore only limited by the atomic shot-noise and even a commercially available quartz should be sufficient to reach ultimate short term stability.
The main goals of the first Swiss primary frequency standard would be to participate in the realization of the international atomic time standard (TAI) and be part of the ground station system for the 2016 ACES (Atomic Clock Ensemble in Space) mission in which a primary atomic clock will be operated in the international space station and will be compared with atomic clocks on Earth.
More informations here : www2.unine.ch/ltf/page-4062_en.html
|Statut||à la fin|
|Délai administratif de soutenance de thèse||2017|