We have successfully grown Thorium, Neptunium, and Uranium doped CaF2 crystals. We are developing an SRR-based spectrometer for NQR spectroscopy. The motivation behind the SRR spectrometer is to have a compact device capable of detecting nuclear resonances in quadrupolar nuclei. This will have applications beyond the nuclear clock.
We have not detected the frequency of the NQR transition yet. However, the work is in progress. The COVID pandemic has delayed many tasks. Meanwhile, we have confirmed the project's feasibility by measuring the electric field gradient on Neptunium in Np:CaF2 using Mossbauer spectroscopy. The measured values are consistent with theoretical predictions from density functional theory (DFT) calculations. We expect to see the NQR transition before the end of the year 2022.
The preliminary results of the Thorium Nuclear Clock Project were presented at the international Thorium conference “Thorium Nuclear Clock Project Workshop” in Berlin, on 6th May 2022. During the period of the project, the team also published a review paper in a prestigious journal in order to spread ideas about the nuclear clock. The project has made great progress. The preliminary results are very encouraging and show that a nuclear clock is a viable option for keeping time. The team is continuing to work on the project and is hopeful that the nuclear clock will be ready for use in the near future.
Beeks, K., Sikorsky, T., Schumm, T., Thielking, J., Okhapkin, M. V., & Peik, E. (2021). The thorium-229 low-energy isomer and the nuclear clock. Nature Reviews Physics, 3(4), 238-248.
RAW data for all NQR and related experiments are kept at ZENODO repository:
https://zenodo.org/record/3931904#.YqsKd3VBzmE(s’ouvre dans une nouvelle fenêtre)
