High spin states in the nucleus Tc-91 have been studied via the fusion
evaporation reaction Ni-58(Ar-36,3p)Tc-91, at 149 MeV and 140 MeV bea
m energy. The OSWS spectrometer, an additional high purity Ge detector
at 162 degrees, and several particle detectors were used to measure g
amma gamma- and particle-gamma coincidences, directional correlations
of oriented states, and line shapes due to Doppler-shift attenuation.
Lifetimes in the 10(-12)-10(-9) S range were measured by the recoil di
stance Doppler-shift method. Some 110 transitions were placed into a l
evel scheme comprising 51 levels reaching up to 12.2 MeV excitation en
ergy and a possible spin I = 49/2 h ($) over bar. A large number of sp
in-parity assignments and E2/M1 mixing ratios and lifetimes were deduc
ed. This extensive data set is used for a detailed test of shell model
calculations. They were performed with different sets of parameters,
within either a restricted pi(p(1/2)), pi(g(9/2)), nu(p(1/2)), and nu(
g(9/2)) configuration space or an enlarged configuration space includi
ng the pi(p(3/2)) and pi(f(5/2)) orbits.