Spectroscopic and decay energy measurements for isotopes with 79 less than or equal to A less than or equal to 84 and N approx. = Z

Heavy-ion reactions induced by beams of 242526Mg and 28Si on targets of 58Ni and 60Ni have been used to produce a number of new or poorly characterized radioactivities with 79 less than or equal to A less than or equal to 84 and N approx. = Z. The helium-jet recoil transfer technique was employed as a means of continuously preparing essentially massless sources of these radioactivities for extensive x-, γ-, and β-ray singles and multiparameter coincidence spectroscopic measurements. The low lying level structure of 80Sr has been revealed for the first time by the decay of a new isotope 80Y (T/sub 1/2/ = 34 s). These measurements have also resulted in a considerable clarification of the decay properties of 79Sr and 8182Y. Decay energies, Q/sub EC/, and nuclidic mass excesses deduced from them, both show progressively larger deviations from the predictions of currently available mass models for these isotopes, especially as the N = Z line is approached. Preliminary decay data are reported for 83Zr and 84Nb, which were both produced as evaporation residues from the 28Si + 58Ni reaction