Magnetic dipole sequences in 83Rb

High-spin states in Rb-83 were populated in the reaction B-11 + Ge-76 at beam energies of 45 and 50 MeV. gamma rays were detected with the spectrometer GASP. The level scheme of 83Rb was extended up to 13.9 MeV. Mean lifetimes of 23 levels were determined using the Doppler-shift-attenuation method. Among the bands newly established is a sequence comprising intense M1 transitions and crossover E2 transitions. This sequence turns out to be irregular and thus shows that magnetic rotation as observed in the neighboring odd-odd isotopes is not realized in this odd-even nuclide. Excited states in Rb-83 were interpreted in terms of the shell model using the model space pi(0f(5/2), 1p(3/2), 1p(1/2), 0g(9/2)) nu(1p(1/2), 0g(9/2)). The configurations predicted for the negative-parity M1 sequence reproduce the M1 transition strengths fairly well.