Welcome to the Website of nuClock!

nuClock is a European project headed for an ambitious goal: the development of a scientific clock that reaches a much higher precision compared to the best clocks that are operated today in some of the world’s finest laboratories. While such clocks use the electrons of an atom as the “pendulum”, we will use the nucleus of a very special atom – Thorium-229 – for setting the rhythm. Once we get our clock working, it can be employed aboard navigation satellites, it can help to synchronize networks, and it might lead astronomers to a better understanding of the universe.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 664732. It will run from 2015 to 2019. Stay with us: it’s sure going to be exciting!

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NEWS

Advances in HHG laser development

Tunable narrow-linewidth lasers, as required for precision spectroscopy, are available only in the visible and infrared wavelength ranges, but not in the VUV range (below 200 nm). Unfortunately, many of the most important transitions lie in this specific wavelength range: building a laser for the VUV range would allow one to perform spectroscopy on the Lyman-alpha transition in hydrogen (121 nm), on He+ ions (60 nm), on a variety of highly charged ions which are relevant for cosmology, and (of course),…

Breakthrough: The first optical spectroscopy of Th-229m ions

So far, all experiments that characterized the Th-229 nuclear isomer employed nuclear physics techniques: gamma spectroscopy, alpha spectroscopy, detection of electrons, coincidence schemes, and the like. For the nuclear optical clock, however, technology out of the quantum optics toolbox will be requires, such as lasers, optical detection, and precision spectroscopy. A recent experiment by the PTB, LMU, and GSI groups now made a huge step into this direction: they performed the first laser spectroscopy…

Theory paper on electron bridge excitation of the isomer

The direct excitation of the nuclear isomeric state is hindered by (1) the technological challenge of building a narrow-linewidth, coherent laser source, and (2) the small coupling of the nucleus to the laser field. These two limitations can be overcome by using an electron bridge process, in which at least part of the required excitation energy is provided by the excitation of a suitable long-lived electronic state. This approach is followed by the ion trap group of E. Peik at PTB. In recent theory…

The best of two worlds: A new proposal for optical spectroscopy of the isomer transition

A handful of experiments have tried optical excitation of the isomer already, unfortunately without success. All of these experiments searched for delayed fluorescence in the optical domain as the smoking gun of an excitation of the isomer. The main obstancle in these experiments can be summarized as follows: The transition linewidth is teeny-weeny small, probably about 0.001 Hz, but the linewidth of excitation sources is very broad, about 100,000,000,000,000 Hz. So it's very unlikely to excite the…

Simon Stellmer receives ERC Starting Grant

Simon Stellmer, nuClock researcher on the Vienna team, has received an ERC Starting Grant. The title of his project reads "Ultracold mercury for a measurement of the EDM". Within this project, he will address one of the most fundamental questions in all of physics: Why does the Universe contain matter? Shortly after the Big Bang, many billion years ago, equal amounts of matter and antimatter were formed. These two types of matter, however, destroy themselves when they come into contact. This process…

Reading material for a nice summer evening

Sitting in your deck chair with nothing to read? We have a solution for you! A few weeks ago, Francisco Ponce of Lawrence Livermore / UC Davis finished his PhD thesis on the topic "High Accuracy Measurement of the Nuclear Decay of U-235m and Search for the Nuclear Decay of Th-229m". In his studies, he searched for the IC electron in the de-excitation of the Th isomer, but was not sensitive to timescales in the µs range. Although eventually not successful, the PhD thesis still makes a nice reading.…

Yudai Shigekawa returns to Japan

Yudai Shigekawa, a PhD student from Osaka, spent a year with the Vienna group. Today, almost exactly one year after his arrival, he disassembled the experimental set-up again, ready to be shipped back to his home university. Yudai constructed an experiment to investigate the decay of U-233 into Th-229. The U-233 sample was sandwiched in between an alpha detector (for measuring alpha particles with high energy and time resolution) and an MCP (to perform spectroscopy on low-energy electrons). The…

nuClock arts collaboration

No joke: there exist peer-reviewed journals on arts! The publications look just like science publications: title, author list, abstract, acknowledgements, list of reference... plus the well-beloved discussions with reviewers. Anyways, the most reputated journal covering the interface between science, technology, and arts is probably Leonardo Magazine, published by MIT Press. This is where we published a study on one of the two projects that nuClock associate Kerstin Ergenzinger is currently working…