Structure of high-spin states in Sr-89 and Sr-90 - art. no. 064315

High-spin states of Sr-89 and Sr-90 were studied via the reactions Se-82(B- 11, p3n) and Se-82(B-11, p2n), respectively, at a beam energy of 37 MeV. Ga mma rays were detected with the GASP spectrometer. The level schemes of Sr- 89 and Sr-90 were extended up to E approximate to 8 MeV and E approximate t o 10 MeV, respectively. Level structures in Sr-89 and Sr-90 were interprete d in terms of the spherical shell model. The calculations were performed in the configuration space (0f(5/2), 1p(3/2), 1p(1/2), 0g(9/2)) for the proto ns and(1p(1/2), 0g(9/2), 1d(5/2)) for the neutrons. High-spin level sequenc es in Sr-89 are characterized by coupling the unpaired d(5/2) neutron to pr oton excitations of the core nucleus Sr-88. An equidistant level sequence w ith DeltaJ=2 found in Sr-90 is well described by the configuration. pi[(0f( 5/2)(-2))(0g(9/2)(2) )]nu (1d(5/2)(2)) favoring even spins.