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Evaluation des performances de la fontaine atomique PHARAO, Participation à l'étude de l'horloge spatiale PHARAO

Abstract : The performances of an atomic frequency standard depend drastically on the observation time of the atoms. The interrogation of laser cooled atoms allows to obtain about half a second interaction time in a fountain geometry. This duration could be much more varied in absence of gravity, and would allow a better trade-off between stability and accuracy. The application of this principle is the aim of the PHARAO project, that should attend to the ACES mission planned in 2006 onboard the International Space Station. The first part of this thesis deals with the cold Cs133 PHARAO fountain. This clock stems from the transformation of a space clock prototype previewsly tested in microgravity. A detailed evaluation of the whole frequency shifts has been carried out, reaching a 7,7 10^(-16) accuracy and a 1,7 10^(-13)tau^(-1/2) short term stability. These values are obtained for 4 10^(5) detected atoms, that provides a good stability-accuracy trade-off. This transportable fountain, built at BNM-SYRTE, has been operating at MPQ in Munich (Germany). The collaboration between the 2 laboratories gave a ~10 improvement factor on the measurement accuracy (1,8 10^(-14)) for the 1S-2S two photons hydrogen transition. In a second part of this thesis, we present the characterisation of 2 elements of the PHARAO space clock: the construction of an etalon extended cavity laser and the test of the phase symmetry between the two interrogating areas of the space cavity.
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Contributor : Michel Abgrall <>
Submitted on : Tuesday, July 1, 2003 - 9:30:15 PM
Last modification on : Monday, December 14, 2020 - 9:55:19 AM
Long-term archiving on: : Friday, April 2, 2010 - 8:12:28 PM


  • HAL Id : tel-00003079, version 1


Michel Abgrall. Evaluation des performances de la fontaine atomique PHARAO, Participation à l'étude de l'horloge spatiale PHARAO. Physique Atomique [physics.atom-ph]. Université Pierre et Marie Curie - Paris VI, 2003. Français. ⟨tel-00003079⟩



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