100 Years of Nuclear Isomers

The common microscopic origin of nuclear metastability manifesting
in the wide energy range from the mega electronvolt excitations of
K-isomers in even-even nuclei to the exceptionally low-energy
excitation of several electronvolts in the ${}^{229m}$Th "clock"
isomer will be discussed. It will be shown in terms of relatively
simple nuclear-structure models that the very fine...

Today’s most precise time and frequency measurements are performed with optical atomic clocks. However, it has been proposed that they could potentially be outper-formed by a nuclear clock, which employs a nuclear transition instead of an atomic shell transition. There is only one known nuclear state that could serve as a nuclear clock us-ing currently available technology, namely the isomeric...

The first excited nuclear isomeric state of Thorium-229 exhibits a special position in the nuclear landscape as it possesses the lowest known excitation energy of all nulcear sates. With an energy of only about 8 eV it conceptually allows for nuclear laser spectroscopy and the development of a nuclear optical clock. Until the present day laser spectroscopy of Thorium-229 has not been achieved...