One work reports a measurement of the energy of the elusive isomeric
state, that may be used to build a nuclear clock to be 8.3 +/- 0.2 eV.
This work has been carried out by a team from LMU Munich with support
from GSI/Mainz, Max-Planck Institute for nuclear Physics, Heidelberg,
and of course the metrology team at TU Wien.

link to: https://arxiv.org/pdf/1905.06308.pdf, opens an external URL in a new window

The other work demonstrates optical X-ray pumping into the Thorium-229
isomer using the 29 keV second excited nuclear level as an intermediate
level. This work has been carried out at the SPring-8 facility by a
large Japanese consortium, again with support by the QME team of TU
Wien.

link to: https://arxiv.org/pdf/1902.04823.pdf, opens an external URL in a new window