Gamma-ray spectroscopy of 79Rb and 81Sr

High spin states in ⁷⁹Rb and ⁸¹Sr were populated through the bombardment of a ⁵⁸Ni target with a ³⁰Si beam at 134 MeV. Gamma rays depopulating the excited states were detected using the EUROGAM phase-2 array. A band of nine transitions has been observed in ⁸¹Sr decaying to the α = - {1}/{2} sequence built on the [303] {5}/{2}^- Nilsson orbit. The decay schemes of several bands in both ⁷⁹Rb and ⁸¹Sr have been extended to higher spin with angular correlation measurements providing firm spin assignments for a number of states. A fork is observed in ⁷⁹Rb after a band crossing at h̷ω ⋍ 0.72 MeV in the α = + {1}/{2} sequence built on the [312] {3}/{2}^- Nilsson orbit. A previously observed cascade of three γ-rays in ⁷⁹Rb has been extended by the addition of ten transitions up to 16 MeV. This has been assigned as a positive parity band built on the [440] {1}/{2}⁺ Nilsson orbit.