The structure of Ru-99 from (alpha,3n) reaction

The results of in-beam investigations of excited states of Ru-99 using the Mo-98(alpha, 3n) reaction are presented. Angular distributions of gamma-ray s and gamma-gamma coincidences have been measured. Excited states have been identified up to an energy of E = 5603 keV and spin of I-pi = 31/2(-). Mea n lifetimes tau have been determined using the DSA method for eleven levels . Aligned angular momenta are discussed and the probable (nu h(11/2)) Origi n of a backbending at frequency about 0.5 MeV was confirmed. The possible r ole of (nu d(5/2)) alignment at frequencies above 0.5 MeV was pointed out.