News

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.