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

Announcement 2017 yearly meeting

The nuClock yearly meeting 2017 will take place in Heidelberg from September 18 to 20 and will be hosted by Adriana's group. We will start on Monday after lunch (such that no-one need to travel on Sunday already) and conclude on Wednesday afternoon. As with previous meetings, we are aiming for a large number of highly specialized talks and vivid discussions. More details willl follow as we are getting closer to the meeting.

Thorium research down under

We just learned about a new Thorium experiment, the first one in the Southern hemisphere! At CSIRO/Griffith University, researchers are currently transforming an already existing Yb ion trap to a Th ion trap. What a brilliant idea! The experiment is based in Brisbane (that's in the South East corner of Queensland), so if you happen do be around or would like to learn more about the experiment, contact Stephen Gensemer or Marcin Piotrowski directly. In a few years' time, we will have Th nuclear clocks…

Save the date: Thorium-229 conference July 9-12, 2018, in Bad Honnef, Germany

The nuClock team will organize an international conference on all topics related to the Thorium-229 isomer. Today, we are proud to announce the date and venue! The conference will take place on July 9 to 12, 2018 in the unique old physics center in Bad Honnef, Germany. The location: The small town of Bad Honnef is beautifully located at the Rhine river, about 45 km south of Cologne. It can nicely be reached by train from the airport of Cologne, as well as from Frankfurt airport. The physics center…

Doctor von der Wense

Yesterday, Lars von der Wense of LMU Munich successfully passed his PhD exam, and he did it with summa cum laude distinction! Lars is the first PhD student funded by the nuClock project to finish his thesis. Congratulations! Lars has been supervised by LMU group leader Peter G. Thirolf. The board of examiners also included fellow nuClock group leaders Adriana Palffy from MPIK Heidelberg and Thomas Udem from MPQ Munich. After the 90-minute torture, Lars was rewarded with the traditional doctoral…

Re-evaluation of the Beck et al. data

The currently most accepted value of the isomer energy is 7.8(5) eV, obtained by the so-called "Beck et al. measurement". In this experiment, researchers from Lawrence Livermore employed a NASA microcalorimeter for a high-resolution gamma measurement of the U-233 decay. Using a clever differencing scheme, they indirectly inferred the energy of the isomer. The final result includes correction terms related to unknown branching ratios. This measurement is now 10 years old, and in the meantime, no…

LMU arXiv paper: feasibility study for electron spectroscopy of the IC electron

A series of recent breakthrough experiments at LMU Munich was able to confirm theoretical and experimental predictions on various properties of the Th-229 isomer. Specifically, the LMU team was able to show (1) that the isomer exists at all, (2) that its energy is somewhere between 6.3 and 18 eV, (3) that the isomer lifetime in Th2+ and Th3+ is longer than a few minutes, (4) that the lifetime in the neutral atom is very short, about 10µs, and (5) that internal conversion (IC) is the dominant decay…

Th-229 isomer lifetime measured in the neutral charge state

The preferred de-excitation pathway of low-energy excited nuclear states is internal conversion (IC). Instead of de-exciting to the ground state via emission of a gamma, they couple to electronic states of similar energy. Their excitation energy is transferred to the electron, which typically leaves the atom and carries away the excess energy. Such a process is common for nuclear states up to 1 MeV, and its probability generally increases with decreasing excitation energy. For the U-235 isomer at…

Transportable optical Sr clock presented by PTB

Building an optical clock based on the Th-229 nuclear transition is the ultimate goal of the nuClock project. We like to claim that such a nuclear clock will be less sensitive to perturbations (because the nucleus is so much smaller than the orbits of valence electrons), offer a supreme quality factor (because the transition energy is so large, and the lifetime of the isomer is so long), and outperform existing clocks in flat-out all respects (well, we become a little bit emotional sometimes). We…