Cold atom Clocks and Applications

Details Cold atom Clocks and Applications Cold atom Clocks and Applications

2005-02-22

arxiv.org/abs/physics/0502117v1

Physics

Atomic Physics

30 pages, 11 figures

Scientific paper

10.1088/0953-4075/38/9/002

This paper describes advances in microwave frequency standards using laser-cooled atoms at BNM-SYRTE. First, recent improvements of the $^{133}$Cs and $^{87}$Rb atomic fountains are described. Thanks to the routine use of a cryogenic sapphire oscillator as an ultra-stable local frequency reference, a fountain frequency instability of $1.6\times 10^{-14}\tau^{-1/2}$ where $\tau $ is the measurement time in seconds is measured. The second advance is a powerful method to control the frequency shift due to cold collisions. These two advances lead to a frequency stability of $2\times 10^{-16}$ at $50,000s for the first time for primary standards. In addition, these clocks realize the SI second with an accuracy of $7\times 10^{-16}$, one order of magnitude below that of uncooled devices. In a second part, we describe tests of possible variations of fundamental constants using $^{87}$Rb and $^{133}$Cs fountains. Finally we give an update on the cold atom space clock PHARAO developed in collaboration with CNES. This clock is one of the main instruments of the ACES/ESA mission which is scheduled to fly on board the International Space Station in 2008, enabling a new generation of relativity tests.

Affiliated with

Also associated with

No associations

Rating

Cold atom Clocks and Applications does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Cold atom Clocks and Applications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cold atom Clocks and Applications will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-472282