First decay study of the very neutron-rich isotope 93 Br

The decay of the mass-separated, very neutron-rich isotope ${}^{93}\mathrm{Br}$ has been studied by \ensuremath{\gamma} spectroscopy. A level scheme of its daughter ${}^{93}\mathrm{Kr}$ has been constructed. Level energies, \ensuremath{\gamma}-ray branching ratios, and multipolarities suggest spins and parities which are in accord with a smooth systematics of the $N=57$ isotones for $Zl~40,$ suggesting the $N=56$ subshell closure still to be effective in Kr isotopes. So far, there is no indication of a progressive onset of deformation in neutron-rich Kr isotopes.