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 on. Please find the link here (or download in the “Publications” section), and an accompanying audio blog post here.

If you want to learn more about the artworks, Kerstin has put a number of photos and videos on her webpage. Kerstin’s work is supported by Daniel Canty, a poet based in Montreal. Check out his webpage as well!

If you want to see the installations in real life, plan for one of the following exhibitions:

  • “unREAL. The Algorithmic Present”, House of electronic arts, Basel (Switzerland), 08.06. – 20.08.2017
  • FEAT exhibition, BOZAR, Brussels (Belgium), 14.09 – 30.9.2017
  • “unREAL”, Chronus Art Center, Shanghai (China), 12.11.2017 – 28.01.2018
  • New paper by the LMU group

    Over the two years, the LMU Munich group has established the detection of internal conversion (IC) electrons as a successful technique to detect the Th-229 isomer. This scheme as already been used to measure the half-life of the isomer in the neutral charge state, but the really important experiment, a measurement of the isomer energy, is still pending. Such an experiment would need to measure the kinetic energy of the IC electron released in the isomer decay. The LMU team just made an important step towards this goal by laying out the theoretical foundation of such an experiment. The publication appeared yesterday in The European Physical Journal A., it is fully Open Access and can be found here.

    Welcome Kjeld Beeks

    A new PhD student joined the nuClock team! Kjeld Beeks from Eindhoven University of Technology just started his PhD in the Vienna group. He will work towards optical excitation and optical detection of the Th-229 isomer transition. Good luck with this challenging work, Kjeld!

    Kjeld Beeks joined the Vienna team.


    Two new papers from Heidelberg

    Adriana’s theory group just published two new papers, both of which might have a significant impact on experiments building on the Th-229 isomer.

    The first paper is a study on a new optomechanical system, which interfaces optical fields and X-rays via an optical cavity. In short, one mirror of an optical cavity is formed by a micro-cantilever, which bears a layer of Th-229 nuclei. These can be excited by X-rays, which impart momentum to the cantilever and change its quantum state, thereby changing the cavity field: a coupling between the optical and X-ray regime! The paper had already been around on the arXiv and has now been published with Sci. Rep., please find the paper here.

    The second paper is of purely theoretical nature and a collaboration with Nikolay Minkov from Sofia, Bulgaria. It discusses a new approach to model the lowest nuclear states in Th-229 and arrives at M1 and E2 transition rates between the isomer and the ground state that are markedly different (substantially smaller) compared to all previous models. Among other explanations (strong IC, isomer energy larger than expected, …), such a small coupling could potentially explain why the optical excitation and de-excitation of the isomer was not observed in past experiments. This work has been accepted for publication with Phys. Rev. Lett. and is already available on the arXiv now.

    Congratulations to Adriana and her team!

    Theory papers to support experiments

    We have built up a considerable backlog in out presentation of papers related to research on the thorium isomer. Here, we highlight a number of theoretical papers that could support experiments searching for the isomer and trying to measure its energy.

    “Magnetic hyperfine structure of the ground-state doublet in highly charged ions 229 Th 89+, 87+ and the Bohr-Weisskopf effect” by E. V. Tkalya and A. V. Nikolaev, published with Phys. Rev. C, link.

    “Bound internal conversion versus nuclear excitation by electron transition: Revision of the theory of optical pumping of the Th-229m isomer” by F. F. Karpeshin and M. B. Trzhaskovskaya, published with Phys. Rev. C, link.

    “Theoretical analysis of the electron bridge process in 229Th3+” by a theory group at PTB in Germany and performed to support the experimental work at PTB, available on the arXiv, link.

    “Impact of the ionization of the atomic shell on the lifetime of the Th-229m isomer” by F. F. Karpeshin et al. in close relation to the LMU Munich experiments, available on the arXiv, link.

    LMU grant proposal accepted

    Frontier research builds on solid funding, and the LMU groups just secured financial support for their upcoming research work. Within the framework of a DFG grant, an electron spectrometer to measure the energy of IC electrons will be constructed. The money is sufficient to buy all the required equipment and LMU researcher Benedict Seiferle will be paid for another three years.


    Congratulations to the LMU team!

    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 needs 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 running on all continents to measure how Earth moves through clouds of Dark Matter. 🙂 So you folks better hurry up with your experiment!

    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 has quite a remarkable history that goes back about 120 years; more information can be found here. Today, it features three state-of-the-art lecture halls and accomodation of about 80 people.

    The conference: The main topic of the conference is the work towards a nuclear clock based on Th-229, and we seek to gather all groups around the world that work towards this goal. Further topics include other novel types of optical clocks (e.g. highly charged ions) and applications in geodesy.

    The registration: Registration will open later this year, we will send around newsletters and post all information on the nuClock website. Seating capacity limits the number of participants to about 80.

    More information will follow. For now, we ask you all to mark your calenders: The meeting will start with a dinner on Sunday, July 8, and end after lunch on Thursday, July 12. To all present nuClock members: This conference will include the internal nuClock yearly meeting 2018.

    Looking forward to see you all at the conference!

    The picturesque building of the physics center.

    The main lecture hall.

    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!

    A snapshot of the PhD exam, the title reads “On the direct detection of the Th-229 nuclear isomer”.

    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 hat prepared by hisPhD colleagues: look at his smile!

    Lars wearing his new hat, fully equipped with an alarm clock linked to a Th-229 nucleus!

    The celebration continued with a large crowd of family & friends in a nearby restaurant.

    His thesis is now available online here.