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Claude Cohen Tannoudji

Prix Nobel en 1997 pour le ralentissement et le piégeage des atomes par la lumière laser.

Ses travaux sont à la source des recherches actuelles de l'IFRAF.



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Accueil du site > Séminaires > LKB > A Tale of Two Paths

A Tale of Two Paths

Exposé de Kirk Madison (Univ. British Columbia, Vancouver)

Vendredi 29 mars 2013, 9 heures 15, exceptionnellement en salle W au département de maths de l’ENS, au 4e étage du batiment Rataud, à l’Ecole normale supérieure, 45 rue d’Ulm 75005 Paris.

Il vous suffira de suivre le couloir passant devant l’habituelle salle de réunion de l’IFRAF, jusqu’au bout, c’est-à-dire au-delà de la porte battante jaune mais avant le petit ascenseur bleu ; la salle W sera alors sur votre droite.

A B S T R A C T

In this talk I will present our recent progress on the realization of a cold atom based primary pressure standard and the promise of triplet state molecules : Li2, LiRb, and RbH

We posit that a stationary atom is an ideal particle flux sensor in an ultra-high vacuum environment, and we demonstrate that sufficiently slow moving sensor atoms can be prepared by laser cooling for the determination of ambient pressures of Ar below 10^-5 Pa.
In brief, the passage of a particle through the collision cross section of the sensor atom is detected by the momentum transfer to it. The incident particle flux is then the single-particle collision rate divided by the total cross section. The latter quantity can be computed from knowledge of the interaction potentials and the former is a measurement of time. _ The main advantage of this detection mechanism is that it is not subject to sensor degradation or calibration drift since the sensor atoms are always the same and the interaction between the sensor atom and the detected particle is an immutable law of nature. These features and the direct link established between particle flux and time makes this method a potential candidate for the realization of a primary pressure standard at and below 10^-5 Pa.

I will also review our recent experimental progress towards the production of ultra-cold triplet state molecules from laser cooled ensemble and I wil discuss why we are so interested and excited about the triplet state.


Voir en ligne : La liste des exposés précédents, avec des photos du séminaire et des fichiers des présentations

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