Nuclear structure of Ho-166 studied in neutron-capture, (d,p), and (d,He-3) reactions - art. no. 044305

The nucleus Ho-166 was studied with thermal and average resonance neutron c apture and with (d,p) and (d,He-3) reactions. We have devoted a large effor t to the measurements of gamma gamma-coincidence spectra in the broad energ y interval 50-6243 keV. From these data and those of previous studies, the level scheme has been developed containing levels grouped into 23 rotationa l bands below 1 MeV. Of these, six bands are new and several others, known previously, have been modified and expanded based upon our experimental dat a. In all, 32 new levels have been identified. Of particular note has been the identification of two rotational bands whose underlying structure consi sts of gamma-vibrational states built upon the two lowest energy quasiparti cle states in Ho-166. Two new Gallagher-Moszkowski matrix elements were det ermined: E-GM(p7/2(-)[523]+/-n5/2(-)[523]) = - 108.5 keV and E-GM{(p7/2(-)[ 523]+/-n7/2(+)[633])+/-Q(22)} = + 138.2 keV. The resultant level scheme is in good agreement with semiempirical and quasiparticle phonon models where residual interactions have been taken into account. Suggestions are given f or further experimentation on Ho-166 level structure using existing technol ogy.