High spin states in neutron-rich 106 Tc nucleus *

Abstract The high spin states of the neutron-rich odd-odd 106 Tc nucleus have been reinvestigated by ob-serving prompt -rays from the spontaneous ssion of 252 Cf. A previously known collective band is con rmedand expanded, and a new collective band is newly identi ed. Several levels in previous report in 106 Tc arereexamined and they belong to the members of a band in 107 Tc. The total Routhiansurface (TRS) calculationsshow that the 106 Tc has triaxial shape. The spins and parities as well as the con gurations for these bandshave been tentatively assigned according to the analysis of the angular momentum alignments.Key words spontaneous ssion, collective band, -transition and level energyPACS 25.85.Ca, 21.10.Re, 23.20.Lv 1 Introduction Research on the high spin states in neutron-richnuclei at A˘100 region is an interesting subject fortheory and experiment, for examples, the sudden on-set of large quadrupole deformation [1, 2] , the superde-formed ground state [2, 3] , the triaxial deformation inMo and Ru isotopes