Vacuum-ultraviolet spectroscopy of the radiative decay of the low-energy isomer in 229Th KU Leuven
The radioisotope 229Th features a nuclear isomer 229mTh with an exceptionally low excitation energy of ≈ 8 eV and a favourable coupling to the environment, making it a candidate for a next generation of optical clocks allowing to study fundamental physics. While first indirect experimental evidence for the existence of such a nuclear state dates from 46 years ago, the proof of existence has been delivered only recently by observing the ...