Mass and half-life measurements of neutron-deficient iodine isotopes

Neutron-deficient iodine isotopes, ¹¹⁶I and ¹¹⁴I, were produced at relativistic energies by in-flight fragmentation at the Fragment Separator (FRS) at GSI. The FRS Ion Catcher was used to thermalize the ions and to perform highly accurate mass measurements with a Multiple-Reflection Time-of-Flight Mass-Spectrometer (MR-TOF-MS). The masses of both isotopes were measured directly for the first time. The half-life of the ¹¹⁴I was measured by storing the ions in an RF quadrupole for different storage times and counting the remaining nuclei with the MR-TOF-MS. The measured half-life was used to assign the ground state to the measured ¹¹⁴I ions. Predictions on the possible α-decay branch for ¹¹⁴I are presented based on the reduced uncertainties obtained for the Q_α-value. Systematic studies of the mass surface were performed with the newly obtained masses, showing better agreement with the expected trend in this mass region.