LEVELS OF IR-185 EXCITED IN THE (ALPHA, XN) REACTIONS

Level properties of 185Ir were investigated by in-beam γ-spectroscopy using (α, 4n) and (α, 6n) reactions with E, ranging from 41 to 77 MeV. A well-developed system of levels built on the h 9 2 Subshell is excited. A band built on the 11 2- isomeric state is also observed. In distinction from heavier Ir isotopes, only a single positive parity band is developed to high-spin states. Two isomers with T 1 2 = 120 ns and 40 ns are found for excitation energies above 2.2 MeV. The experimental results are discussed in terms of rotational models including the Coriolis coupling and providing for a stable triaxial shape of the 185Ir nucleus. © 1979.