Development of a strontium optical lattice clock for the SOC mission on the ISS

The ESA mission "Space Optical Clock" project aims at operating an optical lattice clock on the ISS in approximately 2023. The scientific goals of the mission are to perform tests of fundamental physics, to enable space-assisted relativistic geodesy and to intercompare optical clocks on the ground using microwave and optical links. The performance goal of the space clock is less than $1 \times 10^{-17}$ uncertainty and $1 \times 10^{-15} {\tau}^{-1/2}$ instability. Within an EU-FP7-funded project, a strontium optical lattice clock demonstrator has been developed. Goal performances are instability below $1 \times 10^{-15} {\tau}^{-1/2}$ and fractional inaccuracy $5 \times 10^{-17}$. For the design of the clock, techniques and approaches suitable for later space application are used, such as modular design, diode lasers, low power consumption subunits, and compact dimensions. The Sr clock apparatus is fully operational, and the clock transition in $^{88}$Sr was observed with linewidth as small as 9 Hz.Comment: 12 pages, 8 figures, SPIE Photonics Europe 201

Recurrent Bacteremia, a Complication of Cyanoacrylate Injection for Variceal Bleeding: Report of Two Cases and Review of the Literature

We report the first description of recurrent bacteremia in two patients after cyanoacrylate injection for gastric varices bleeding treated with antibiotics alone. Adapted and prolonged antibiotic treatment allowed a complete resolution of the infection with no relapse after more than 6 months. According to recent data, prophylactic antibiotics should be further investigated for patients with bleeding varices undergoing cyanoacrylate injection

Development of a strontium optical lattice clock for the SOC mission on the ISS

Ultra-precise optical clocks in space will allow new studies in fundamental physics and astronomy. Within an European Space Agency (ESA) program, the Space Optical Clocks (SOC) project aims to install and to operate an optical lattice clock on the International Space Station (ISS) towards the end of this decade. It would be a natural follow-on to the ACES mission, improving its performance by at least one order of magnitude. The payload is planned to include an optical lattice clock, as well as a frequency comb, a microwave link, and an optical link for comparisons of the ISS clock with ground clocks located in several countries and continents. Within the EU-FP7-SPACE-2010-1 project no. 263500, during the years 2011-2015 a compact, modular and robust strontium lattice optical clock demonstrator has been developed. Goal performance is a fractional frequency instability below 1x10^{-15}, tau^{-1/2} and a fractional inaccuracy below 5x10^{-17}. Here we describe the current status of the apparatus' development, including the laser subsystems. Robust preparation of cold {88}^Sr atoms in a second stage magneto-optical trap (MOT) is achieved.Comment: 27 Pages, 15 figures, Comptes Rendus Physique 201

Gyromètre à atomes froids de grande sensibilité

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