THE N=47 SHELL-MODEL NUCLEUS TC-90

Lifetimes of high spin states in the nucleus Tc-90 have been measured via the fusion evaporation reactions Ni-58(Ar-36, 3pn)Tc-90 at 140 MeV and Ni-58(Cl-35, 2pn)Tc-90 at 120 MeV beam energy. The OSIRIS spectro meter as well as a new neutron-gamma-coincidence setup were used to me asure lifetimes in the 10(-12) - 10(-9) s range by the recoil distance Doppler-shift method. By means of gamma-multiplicity and neutron-gate d spectra fifteen lifetimes were deduced. The experimental branching r atios and transition probabilities are compared to predictions of shel l model calculations in a restricted pi(p(1/2)), pi(g(9/2)), nu(p(1/2) ), and nu(g(9/2)) configuration space. In most cases the agreement wit h the calculations using the Gross-Frenkel parameters is striking but the results for several yrare states very sensitively depend on the re sidual interaction used.