Decay studies of N≈Znuclei from 78Yto 102Sn

Neutron deficient nuclei near 100 Sn have been produced by projectile fragmentation of a 1 A-GeV 112 Sn beam in a beryllium target. The fragments were separated in the magnetic spectrometer FRS at GSI, Darmstadt. The unambiguously identified ions were stopped in a highly segmented silicon strip detector stack which was designed to measure the halflives and the total energy of emitted particles with very low background and high efficiency. We were able to study 102 Sn in decay spectroscopy for the first time and establish a decay scheme for the daughter nuclide 102 In . With the measurement of the halflife and the Q-value the Gamov-Teller strength could be deduced. Additionally the Q-value of 98 Cd was measured with high precision and we obtained the halflives of 101 Sn , 103 Sn and 100 In and the absolute branching ratio of beta-delayed proton emission of 101 Sn . We report halflives of rp-process waiting point nuclei between 80 Zr and 92,93 Pd and the observation of very fast decays for the heaviest odd-odd N =Z nuclei, 90 Rh , 94 Ag and 98 In , in agreement with superallowed Fermi transitions. In addition halflives of 75 Sr , 77 Y , 79 Zr , 83 Mo , 87 Tc , 91,92,93 Rh and 99 In were measured. Finally, with our highly efficient identification system we were able to identify two new nuclei, 76 Y and 78 Zr , close to the proton dripline.