Search

High-spin states in the neutron-deficient isotope Cd-104 were populated using the Cr-50(Ni-58,4p)Cd-104 reaction at a beam energy of 250 MeV The level scheme has been extended using triple gamma-ray coincidences to a spin of 29h and an excitation energy of 18.2 MeV. Several collective structures involving the excitation of h(11/2) neutrons have been observed to spins approaching 30h. The high-spin structure has been compared to the results of cranked Nilsson-Strutinsky calculations.

High-spin states have been identified in doubly odd 112I, up to a spin approaching 30h(cross), using the 58Ni(58Ni,3pn gamma ) reaction. Gamma-ray coincidence data were collected with the Eurogam spectrometer coupled to the Daresbury recoil separator. The results represent the lightest doubly odd iodine isotope for which gamma -ray transitions have been identified.

The 92Mo(27Al,2pn gamma ) reaction has been used to populate high-spin states in doubly odd 116I. Evidence for a termination of the collective rotational states is observed at spin Ipi =(23-). Total Routhian surface calculations have been performed in order to interpret the structure of this non-collective state which is found to be closely related to termination states seen in several neighbouring odd-A iodine isotopes.

The 92Mo(27Al, 2p2n gamma ) reaction has been used to populate high-spin states in 115I. The dominant structures are associated with pi h112/(550)1/2- and pi g92/(404)9/2+ orbitals. At the highest spins, favoured states with Ipi =43/2- and 51/2-, associated with non-collective oblate configurations are yrast. The systematics of such states in the odd-A 115-121I isotopes are discussed.

The quadrupole moments for collective structures in the odd proton (Z = 59) , and nuclei have been measured using the Doppler-shift attenuation method. New information is presented on the shape-driving behaviour of the [404] proton and [541] (, ) neutron Nilsson configurations. While the involvement of the former orbital leads to quadrupole deformations that are comparable to those observed for the so-called superdeformed bands in this mass region, the values for structures that include the 1/[541] neutron are found to lie intermediate between those observed for normally deformed and superdeformed bands.