Nuclear charge radii of ${}^{229}$Th from isotope and isomer shifts

M. S. Safronova, S. G. Porsev, M. G. Kozlov +5

The isotope ${}^{229}$Th is unique in that it possesses an isomeric state of only a few eV above the ground state, suitable for nuclear laser excitation. An optical clock based on th…