EURAMET TC-TF meeting 2017 Progress on the OC18 project was presented at the annual meeting of the EURAMET Technical Committee for Time and Frequency, held at the Spanish Royal Naval Institute and Observatory (ROA – Real Instituto y Observatorio de la Armada) in San Fernando on 8th – 9th March 2017. Optical atomic clock searches for dark matter One of the publications supported by this project, “Experimental constraint on dark matter detection with optical atomic clocks” has been published in the high-impact journal Nature Astronomy, and received widespread coverage with press releases and articles in the popular press. The paper demonstrates how optical atomic clocks can be used to address fundamental physics questions concerning the nature of dark matter and its coupling to atoms. Beyond its gravitational interactions at the galactic scale, little is known about the nature of dark matter. The paper reports that a single optical atomic clock can be used as a detector for the hypothetical dark matter in the form of stable topological defects, slight variations on the quantum field created at the birth of the universe, containing energy. In the presence of such a defect, the fine-structure constant should be slightly modified. The reported experiment has exploited differences in the susceptibilities to the fine-structure constant of essential parts of an optical atomic clock, i.e. the atoms and the cavity. The level of constraint on the strength of atomic coupling to hypothetical dark-matter cosmic objects was found to exceed the previously reported limits by more than three orders of magnitude. OC18 M9 progress meeting The month-9 progress meeting was held at PTB on Monday 13th – Tuesday 14th February, 2017. Representatives from all 12 partners were present and it was a very productive meeting, discussing progress so far and planning future activities. School on Optical Clocks 2018 Following a successful summer school in 2015, we are pleased to announce a second School on Optical Clocks to be held 10th – 14th September 2018 in Aosta Valley, Italy. The school will be hosted by INRIM and the other OC18 partners, and will be aimed at PhD students, post-docs, young scientists and engineers in the field with a strong focus on training and education. The scope will include tutorials and the latest advances in frequency metrology and atomic frequency standards. We welcome applications from anyone interested in learning more about optical clocks and their developments through lectures from international experts in the field. Ion-trap exhibited at Quantum Technologies Showcase A prototype single-ion trap, being developed at NPL in conjunction with OC18, was exhibited at the UK’s 2016 National Quantum Technologies Showcase on 3rd November 2016. This was a one-day event highlighting quantum technologies that have the potential for the creation of new markets and economic benefit. Two Researcher Mobility Grants awarded Congratulations to two researchers from ROA (Royal Observatory of the Spanish Navy), Spain on their successful applications for Researcher Mobility Grants in the 2016 call. Héctor Álvarez Martínez will be hosted by OBSPARIS at SYRTE for 18 months to investigate an alternative approach to clock laser stabilisation, using a cavity with several resonators bored in the same spacer. María del Carmen Vélez López will be a guest worker at INRIM for 13 months, developing laser systems for a second ytterbium optical lattice clock, and carrying out frequency comparisons between different atomic clocks. OC18 kick-off meeting The kick-off meeting for the OC18 project was held at NPL on 15th – 16th June, 2016, with representatives from NPL, CMI, INRIM, LNE, OSBPARIS PTB, TUBITAK, VTT, LUH, UMK and CNRS present. EURAMET TC-TF meeting 2016 An introduction to the OC18 project was presented at the annual meeting of “EURAMET Technical Committee for Time and Frequency”, held at MIKES Metrology, VTT Technical Research Centre of Finland on 1st – 2nd March, 2016.