Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Conference on Precision Electromagnetic Measurements

Test of a space cold atom clock prototype in absence of gravity

P. Lemonde, Philippe Laurent, E. Simon, Giorgio Santarelli, Andr  Clairon, Ch Salomon, N. Dimarcq, P. Petit

Published Nov 27, 2002• 9 citations
Publisher

Abstract

In space, thanks to micro-gravity conditions, a clock using laser cooled atoms is expected to have a better performance than on Earth. We have constructed a prototype of this space clock. It was tested in the absence of gravity of aircraft parabolic flights, yielding an atomic resonance with a width of 7 Hz, twice narrower than on Earth.
DOI
10.1109/cpem.1998.699815

Related papers

Test of a space cold atom clock prototype in the absence of gravity

P. Lemonde, Philippe Laurent, E. Simon +5 more

We describe a space cold atom clock prototype and its operation on board an aircraft. We have recorded the atomic resonance in zero gravity during parabolic flights. This experiment must be considered as an essential step toward the construction of a space clock using cold atoms. In a microgravity environment, a cold atomic clock would outperform all ground-based clocks. By the year 2002, we plan to operate a cold atom clock on board the international space station. This mission is called Atomic Clock Ensemble in Space (ACES). We have also performed a preliminary accuracy evaluation of the prototype. The interrogation of the cold atoms is performed inside a TE/sub 013/ cavity. On earth, the phase variations of the field induce a relative frequency shift of about 1/spl times/10/sup -13/. Although the frequency shift is expected to strongly decrease in microgravity, this cavity does not seem suitable for a 1/spl times/10/sup -16/ frequency uncertainty.

IEEE Transactions on Instrumentation and Measurement•Apr 1, 1999•14 citations

A cold atom clock in absence of gravity

Philippe Laurent, P. Lemonde, E. Simon +6 more

We describe the operation of a cold atom clock in reduced gravity. We have recorded the cesium hyperfine resonance signal at a frequency near 9.2 GHz in the gravity environment produced by jet plane parabolic flights. With a resonance width of 7 Hz, the device operated in a regime which is not accessible on earth. In the much lower gravity level of a satellite, our cold cesium clock would outperform the fountains with a potential accuracy of . This experiment paves the way to unprecedented performance in space applications such as tests of general relativity, global time dissemination, astronomy and geodesy.

The European Physical Journal D•Jan 1, 1998•66 citations

Tests of Cold Atom Clock in Orbit

Liang Liu, Desheng Lü, Weibiao Chen +23 more

Since the atomic clock was invented, its performance has been improved for one digit every decade until 90s of last century when the traditional atomic clock almost reached its limit. With laser cooled atoms, the performance can be further improved, and nowadays the cold atom based clocks are widely used as primary frequency standards. Such a kind of cold atom clocks has great applications in space. This paper presents the design and tests of a cold atom clock (CAC) operating in space. In microgravity, the atoms are cooled, trapped, launched and finally detected after being interrogated by microwave field with Ramsey method. The results of laser cooling of atoms in microgravity in orbit are presented and compared with that on ground for the first time. That the full width at half maximum (FWHM) of obtained central Ramsey fringes varies linearly with launching velocity of cold atoms shows the effects of microgravity. With appropriate parameters, a closed-loop locking of the CAC is realized in orbit and the estimated short term frequency stability of $3.0\times 10 ^{-13}/\sqrt{τ}$ has been reached.

arXiv:1709.03256•Sep 11, 2017•4 citations

Proposal of A New Space Atomic Frequency Standard

Xinqi Wang, Yuzhu Wang

A new prototype atomic fountain clock working in the micro-gravity environment is proposed. The successive Ramsey interactions of cold atoms and oscillatory field are realized by means of computer-controlled periodic motion of oscillatory field while the cold atoms stay still relatively in the prototype. Preliminary analyses in comparison with the atomic fountain clock working on the ground show that higher stability is obtainable in the prototype.

Chinese Physics Letters•Jul 1, 1999•2 citations

Compact Cold-Atom Clock for Onboard Timebase: Tests in Reduced Gravity

Mehdi Langlois, L. De Sarlo, David Holleville +3 more

Improving global navigation satellite systems (GNSS) requires a more stable basis of timekeeping. Cold-atom clocks are currently the most accurate time references, but are large. This article presents an atomic clock, ``Rubiclock'', that is compact and portable, thanks to a fiber-based laser bench, isotropic light cooling, and atoms that remain motionless during the operating sequence. This configuration gives the clock an important benefit in microgravity; measurements performed on 0-$g$ flights show better stability than on the ground. The stability that Rubiclock could achieve in a satellite makes it a good candidate for the next generation of GNSS.

arXiv:1812.01658•Physical Review Applied•Dec 4, 2018•26 citations

Physics package based on intracavity laser cooling 87Rb atoms for space cold atom microwave clock

Siminda 思敏达 Deng 邓, Wei 伟 Ren 任, Jingfeng Xiang +9 more

Abstract This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation, microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2 × 10−12 τ −1/2 with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.

Chinese Physics B•May 15, 2024•4 citations
We describe a space cold atom clock prototype and its operation on board an aircraft. We have recorded the atomic resonance in zero gravity during parabolic flights. This experiment must be considered as an essential step toward the construction of a space clock using cold atoms. In a microgravity environment, a cold atomic clock would outperform all ground-based clocks. By the year 2002, we plan to operate a cold atom clock on board the international space station. This mission is called Atomic Clock Ensemble in Space (ACES). We have also performed a preliminary accuracy evaluation of the prototype. The interrogation of the cold atoms is performed inside a TE/sub 013/ cavity. On earth, the phase variations of the field induce a relative frequency shift of about 1/spl times/10/sup -13/. Although the frequency shift is expected to strongly decrease in microgravity, this cavity does not seem suitable for a 1/spl times/10/sup -16/ frequency uncertainty.
We describe the operation of a cold atom clock in reduced gravity. We have recorded the cesium hyperfine resonance signal at a frequency near 9.2 GHz in the gravity environment produced by jet plane parabolic flights. With a resonance width of 7 Hz, the device operated in a regime which is not accessible on earth. In the much lower gravity level of a satellite, our cold cesium clock would outperform the fountains with a potential accuracy of . This experiment paves the way to unprecedented performance in space applications such as tests of general relativity, global time dissemination, astronomy and geodesy.
Since the atomic clock was invented, its performance has been improved for one digit every decade until 90s of last century when the traditional atomic clock almost reached its limit. With laser cooled atoms, the performance can be further improved, and nowadays the cold atom based clocks are widely used as primary frequency standards. Such a kind of cold atom clocks has great applications in space. This paper presents the design and tests of a cold atom clock (CAC) operating in space. In microgravity, the atoms are cooled, trapped, launched and finally detected after being interrogated by microwave field with Ramsey method. The results of laser cooling of atoms in microgravity in orbit are presented and compared with that on ground for the first time. That the full width at half maximum (FWHM) of obtained central Ramsey fringes varies linearly with launching velocity of cold atoms shows the effects of microgravity. With appropriate parameters, a closed-loop locking of the CAC is realized in orbit and the estimated short term frequency stability of 3.0×10−13/τ3.0\times 10 ^{-13}/\sqrt{τ}3.0×10−13/τ​ has been reached.
Improving global navigation satellite systems (GNSS) requires a more stable basis of timekeeping. Cold-atom clocks are currently the most accurate time references, but are large. This article presents an atomic clock, ``Rubiclock'', that is compact and portable, thanks to a fiber-based laser bench, isotropic light cooling, and atoms that remain motionless during the operating sequence. This configuration gives the clock an important benefit in microgravity; measurements performed on 0-ggg flights show better stability than on the ground. The stability that Rubiclock could achieve in a satellite makes it a good candidate for the next generation of GNSS.
Abstract This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation, microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2 × 10−12 τ −1/2 with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.