Isomeric states in neutron-deficient A~80-90 nuclei populated in the fragmentation of ¹⁰⁷Ag

Abstract

The relativistic projectile fragmentation of a 750 MeV per nucleon beam of ¹⁰⁷Ag was used to populate isomeric states in neutron-deficient nuclei around A=80-90. Reaction products were separated and unambiguously identified using the GSI FRagment Separator (FRS) and its ancilliary detectors. At the final focal plane, the fragments were slowed from relativistic energies by means of an aluminium degrader and implanted in a passive stopper in the center of the high efficiency, high granularity Stopped Rare Isotope Spectroscopic INvestigation at GSI (RISING) germanium array. This allowed the identification of excited states in the N=Z nuclei ₄₃⁸⁶Tc and, for the first time, ₄₁⁸²Nb. Isomeric states have also been identified for the first time in ^{87, 88}Tc, and a previously unreported isomer was observed in ⁸⁴Nb. Experimental results are presented along with a discussion on the structure of these nuclei based on interpretations provided by several theoretical models.