Lifetimes of High-Spin States in the $\pi$i$_{13 / 2}$ Band of $^{173}$Re

Lifetime measurements on the i{sub 13/2} band built on the proton configuration 1/2{sup +}[660] in {sup 173}Re have been carried out by the Doppler-broadened line shape method with the use of the GAMMASPHERE array in an early-implementation arrangement. Lifetimes of the stretched E2 transitions from states of spin 41/2{sup +}{endash}69/2{sup +} in this band were measured, and the transition quadrupole moments calculated from these lifetimes are consistent (average Q{sub t}=8.1{plus_minus}0.5eb) with a large and near-constant deformation ({beta}{sub 2}{approx}0.29) over the frequency range of {h_bar}{omega}=0.29{endash}0.47 MeV. This result attests to the strong deformation-driving effect of the intruder {pi}i{sub 13/2} orbital when it lies just above the Fermi surface. From thin-target measurements, it was possible to add three new levels to this band and to determine that the experimental aligned angular momenta gradually evolve over a large frequency range and level off with a total gain characteristic of alignment by i{sub 13/2} neutrons. Calculations carried out for diabatic configurations give a satisfactory accounting of the alignment gain. However, because of the large interaction between crossing bands, a more meaningful description of the deformation pattern in this band was achieved through calculations of the spin-adiabatic type. Both calculations are discussed and compared withmore » the experimental results. {copyright} {ital 1997} {ital The American Physical Society}« less