Level structure of ~(99)Rh at high spins

摘要

High spins states in ~(99)Rh were populated via the ~(66)Zn(~(37)Cl, 2p2n) ~(99)Rh 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 ～ 25h and an excitation energy of about E_x ～ 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 ～ 25h is suggested to be based on (π g_(9/2)~3) direct X (v g_(7/2)~2) quasi-particle excitations.