HIGH-SPIN SHELL-MODEL STATES IN THE ISOTOPE TC-90(43)47

High spin states in the nucleus Tc-90 have been identified for the first time via the fusion evaporation reaction (Ni(Ar,3pn)Tc)-Ni-58-Ar-36-Tc-90, at 149 MeV beam energy. The OSIRIS spectrometer with an additional high purity Ge detector at 162-degrees and several particle detectors were used to measure gammagamma and particle-gammagamma coincidences, directional correlations of oriented states (DCO's), and line shapes due to Doppler-shift attenuation (DSA). Furthermore, an angular distribution experiment was performed with the reaction (Ni(Cl,2pn)Tc)-Ni-58-Cl-35-Tc-90, at 120 MeV beam energy. Some 90 transitions were placed into a level scheme comprising 45 levels reaching up to a possible spin I = 26hBAR at 11.2 MeV excitation energy. Definite spin assignments for more than half of the levels were made via angular distribution coefficients and DCO ratios. Shell model calculations were performed in a restricted configuration space consisting of only the P1/2 and g9/2 orbitals. The level scheme can be reproduced very well up to spin I = 21hBAR. The predicted structure of the states is discussed and compared to those of neighboring isotopes.