Design of the cold atom PHARAO space clock and initial test results

Laurent, Philippe; Abgrall, M.; Jentsch, C.; Lemonde, P.; Santarelli, G.; Clairon, A.; Maksimovic, I.; Bize, S.; Salomon, Christophe; Blonde, Didier; Vega, J.F.; Grosjean, Olivier; Picard, F.; Saccoccio, M.; Chaubet, M.; Ladiette, N.; Guillet, L.; Zenone, Isabelle; Delaroche, C.; Sirmain, C.

doi:10.1007/s00340-006-2396-6

Cited by 94 publications

(44 citation statements)

References 6 publications

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“…It is essentially based on the PHARAO clock [5,6], developed to engineering model level by CNES in the framework of the ESA ISS mission ACES. In EGE, this clock is upgraded using the microwave-optical local oscillator.…”

Section: Overviewmentioning

confidence: 99%

“…The most performing clocks available at the time, hydrogen masers, were used for this experiment. The ACES (Atomic Clock Ensemble in Space) mission planned to fly on the ISS in 2014 seeks to improve the determination by a factor 25, by using a cold atom clock (PHARAO) and a hydrogen maser [5,6]. Recent progress on cold atom clocks in the optical domain and in optical technology enable performing this fundamental test with orders of magnitude better sensitivity.…”

Section: Introductionmentioning

confidence: 99%

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Einstein Gravity Explorer–a medium-class fundamental physics mission

et al. 2008

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The Einstein Gravity Explorer mission (EGE) is devoted to a precise measurement of the properties of space-time using atomic clocks. It tests one of the most fundamental predictions of Einstein's Theory of General Relativity, the gravitational redshift, and thereby searches for hints of quantum effects in gravity, exploring one of the most important and challenging frontiers in fundamental physics. The primary mission goal is the measurement of the gravitational redshift with an accuracy up to a factor 10 4 higher than the best current result. The mission is based on a satellite carrying cold atombased clocks. The payload includes a cesium microwave clock (PHARAO), an optical clock, a femtosecond frequency comb, as well as precise microwave time transfer systems between space and ground. The tick rates of the clocks are continuously compared with each other, and nearly continuously with clocks on earth, during the course of the 3-year mission. The highly elliptic orbit of the satellite is optimized for the scientific goals, providing a large variation in the gravitational potential between perigee and apogee. Besides the fundamental physics results, as secondary goals EGE will establish a global

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Section: Overviewmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Einstein Gravity Explorer–a medium-class fundamental physics mission

et al. 2008

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“…Most of the subsystems and components are similar or can be derived from the PHARAO project [1]. Estimations of mass and power budget take advantage of these similarities.…”

Section: Description Of the Payloadmentioning

confidence: 99%

“…The SAGAS accelerometer is based on cold Cs atom technology derived to a large extent from the PHARAO space clock built for the Atomic Clock Ensemble in Space (ACES) mission [1]. The PHARAO engineering model has recently been tested with success, demonstrating the expected performance and robustness of the technology.…”

Section: Introductionmentioning

confidence: 99%

Quantum physics exploring gravity in the outer solar system: the SAGAS project

et al. 2008

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We summarise the scientific and technological aspects of the Search for Anomalous Gravitation using Atomic Sensors (SAGAS) project, submitted to ESA in June 2007 in response to the Cosmic Vision 2015-2025 call for proposals. The proposed mission aims at flying highly sensitive atomic sensors (optical clock, cold atom accelerometer, optical link) on a Solar System escape trajectory in the 2020 to 2030 time-frame. SAGAS has numerous science objectives in fundamental physics and Solar System science, for example numerous tests of general relativity and the exploration of the Kuiper belt. The combination of highly sensitive atomic sensors and of the laser link well adapted for large distances will allow measurements with unprecedented accuracy and on scales never reached before. We present the proposed mission in some detail, with particular emphasis on the science goals and associated measurements and technologies.

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“…This is the energy scale for collisions in PHARAO, a microgravity laser-cooled cesium clock scheduled to launch soon as part of the ACES mission [20]. Additionally, precise measurements of scattering phase shifts, or equivalently scattering lengths, near narrow Feshbach resonances may provide high sensitivity to the time variation of fundamental constants [21,22].…”

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confidence: 99%

Atomic Clock Measurements of Quantum Scattering Phase Shifts Spanning Feshbach Resonances at Ultralow Fields

Bennett¹,

Gibble²,

Kokkelmans³

et al. 2017

Phys. Rev. Lett.

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We use an atomic fountain clock to measure quantum scattering phase shifts precisely through a series of narrow, low-field Feshbach resonances at average collision energies below 1 µK. Our low spread in collision energy yields phase variations of order ±π/2 for target atoms in several F, mF states. We compare them to a theoretical model and establish the accuracy of the measurements and the theoretical uncertainties from the fitted potential. We find overall excellent agreement, with small statistically significant differences that remain unexplained.

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Design of the cold atom PHARAO space clock and initial test results

Cited by 94 publications

References 6 publications

Einstein Gravity Explorer–a medium-class fundamental physics mission

Einstein Gravity Explorer–a medium-class fundamental physics mission

Quantum physics exploring gravity in the outer solar system: the SAGAS project

Atomic Clock Measurements of Quantum Scattering Phase Shifts Spanning Feshbach Resonances at Ultralow Fields

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