Level structure of 99Rh at high spins

High spins states in Rh-99 were populated via the Zn-66(Cl-37, 2p2n)Rh-99 reaction at an incident beam energy of 130 MeV. Seventeen new transitions have been observed in the present study and the level scheme has now been extended up to a spin of J similar to 25 (h) over bar, and an excitation energy of about E-x similar to 10 MeV. The observation of a positive parity E2 cascade based on the 9/2(+) isomeric level is suggestive of collective behaviour in this nucleus up to high spins. Spherical shell model (within restricted model space) and Cranked shell model calculations were performed to obtain an insight into the observed level structure. The new collective band observed up to a spin of J similar to 25 (h) over bar, is suggested to be based on (pi g(9/2)(3))x(upsilon g(7/2)(2)) quasi-particle excitations.