INTRUDER BANDS EXTENDED IN RE-175 AND IR-177 - DEFORMATION CHANGES AND INTERACTION AT THE ALIGNMENT OF I(13 2) NEUTRONS/

The pi i(13/2)(1/2(+)[660]) and pi h(9/2)(1/2(-)[541]) bands of Re-175 and Ir-177 are extended to high spins with the reactions Dy-161(F-19, 5n)Re-175 and Nd-146(Cl-35, 4n)Ir-177. Band crossings are observed wh ich are attributed to the alignment of i(13/2) neutrons. In the case o f the pi i(13/2) bands, a study of the alignments implies a reduction in deformation at the crossing. In Ir-177 the yrare extensions of the one- and three-quasiparticle pi i(13/2) bands are observed for the fir st time, enabling relative quadrupole moments to be deduced. These sup port a loss of deformation in the three-quasiparticle pi i(13/2) bands . The interaction between the bands is 77.3 keV. Therefore, up-bends a t low frequency in the pi i(13/2) bands are attributed to deformation effects rather than strong interactions.