β+-endpoint measurements near100Sn and146Gd

With a summation-free ß⁺-endpoint spectrometer the ß⁺-decay energies of¹⁰⁴Sn,¹⁴⁷Tb,^{148, 149}Dy,¹⁴⁹Ho,¹⁵⁰Er, and¹⁵¹Tm were remeasured with improved accuracy. Combined with known proton and alpha decay energies, the resulting Q_EC values lead to atomic masses of very neutron-deficient isotopes including nuclei beyond the proton drip-line such as¹⁰⁹I and¹¹³Cs. Furthermore, the Gamow-Tellerß-strength of the even-even nuclei¹⁰⁴Sn,¹⁴⁸Dy, and¹⁵⁰Er is reevaluated with reduced uncertainty.