High spin states in the ${}_{}{}^{191}{}_{}{}^{}\mathrm{Tl}$ nucleus have been populated via the ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tb}$ ${(}^{36}$S,4n) reaction at 165 MeV. Two weakly populated rotational bands have been observed with properties (energy spacings and dynamic moments of inertia) very similar to those of other superdeformed bands in the A∼190 region. The two bands can be interpreted as signature partners which exhibit some signature splitting for rotational frequencies ħω≥0.2 MeV. They are interpreted within the framework of cranked Woods-Saxon calculations as being based on the proton ${\mathit{i}}_{13/2}$(Ω=5/2) intruder orbital, in agreement with pairs of superdeformed bands seen in neighboring odd Tl nuclei.

• Received 13 April 1993

DOI:https://doi.org/10.1103/PhysRevC.49.718