The decay of the very neutron-rich nucleus ${}^{100}\mathrm{Rb}$ has been studied by γ spectroscopy of online mass-separated samples. Schemes for β decay to ${}^{100}\mathrm{Sr}$ and $\beta n$ decay to ${}^{99}\mathrm{Sr}$ are presented. New sets of transitions in ${}^{99}\mathrm{Sr}$ and ${}^{100}\mathrm{Sr}$ with identical energies are observed. All identical bands so far observed in neutron-rich Sr isotopes obey a simple energy rule valid for even-even, odd-even, and odd-odd bands.

• Received 20 December 2000

DOI:https://doi.org/10.1103/PhysRevC.63.054302