# The 229-thorium isomer: doorway to the road from the atomic clock to the nuclear clock

@article{Thirolf2019The2I,
title={The 229-thorium isomer: doorway to the road from the atomic clock to the nuclear clock},
author={Peter G. Thirolf and Benedict Seiferle and Lars C. von der Wense},
journal={Journal of Physics B: Atomic, Molecular and Optical Physics},
year={2019},
volume={52}
}
• Published 25 September 2019
• Physics
• Journal of Physics B: Atomic, Molecular and Optical Physics
The elusive ‘thorium isomer’, i.e. the isomeric first excited state of 229Th, has puzzled the nuclear and fundamental physics communities for more than 40 years. With an exceptionally low excitation energy and a long lifetime it represents the only known candidate so far for an ultra-precise nuclear frequency standard (‘nuclear clock’), potentially able to outperform even today’s best timekeepers based on atomic shell transitions, and promising a variety of intriguing applications. This…
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