Entries by Simon Stellmer

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 […]

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 […]

Theory paper on laser-induced de-excitation of the isomer

The exact energy of the isomer is still unknown, but there is good news: the recent experiments at LMU in Munich have shown that a 2 percent fraction of U-233 recoil ions are in the isomeric state. Such ions can now be used for spectroscopy. In a recent publication, researchers from MPIK in Heidelberg and […]

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 […]

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, […]

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 […]

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 […]

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 […]

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, […]

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!