The ($n, n^{\prime }\gamma$) reaction has been used to study low-lying collective excitations in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Os}$. Measurements of $\gamma$-ray excitation functions at incident neutron energies from 1.0 to 3.0 MeV and detailed $\gamma$-ray angular distributions at 2.5-MeV neutron energy have led to the placement of many new levels in a level scheme now incorporating 54 levels below 2.4 MeV. In many cases, the assignment of a unique spin-parity has been possible. The positive-parity states compare favorably with interacting boson approximation and boson expansion theory calculations, except for the $0_3^{+}$ excitation, which is inconsistent with predictions of both models. No negative-parity band structure is apparent.

NUCLEAR REACTIONS ${}_{}{}^{192}{}_{}{}^{}\mathrm{Os}(n, n^{\prime }\gamma )$, $E_n=1.0-3.0\mathrm{}$ MeV; measured $E_{\gamma }$, $I_{\gamma }$, $\sigma (E, E_{\gamma }, {\theta }_{\gamma })$. ${}_{}{}^{192}{}_{}{}^{}\mathrm{Os}$ deduced levels, branching ratios, $J$, $\pi$. Compared levels and branching ratios to theory. Enriched target, Ge(Li) detector, time-of-flight background suppression.

• Received 13 September 1982

DOI:https://doi.org/10.1103/PhysRevC.27.2608