Magnetic dipole sequences in Rb83

Abstract

High-spin states in Rb83 were populated in the reaction B11+Ge76 at beam energies of 45 and 50 MeV. γ rays were detected with the spectrometer GASP. The level scheme of Rb83 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 Rb83 were interpreted in terms of the shell model using the model space π(0f5/2,1p3/2,1p1/2,0g9/2) ν(1p1/2,0g9/2). The configurations predicted for the negative-parity M1 sequence reproduce the M1 transition strengths fairly well. © 2009 The American Physical Society.