Spectroscopy of the long-lived excited state in neutron-deficient 195,197,199Po by precision mass measurements

Precision masses of neutron-deficient ¹⁹⁵,¹⁹⁷,¹⁹⁹Po used to pin down a long-lived excited state that sits close in mass to the ground state.

ISOLTRAP Penning-trap mass spectrometry of polonium beams from ISOLDE, resolving the isomer from the ground state by the mass difference.

A long-lived isomer that is almost degenerate with the ground state changes decay paths and laser-spectroscopy assignments. The masses turn that isomer from a suspicion into a measured state.