The ${}_{}{}^{194,196,198}{}_{}{}^{}\mathrm{Pt}\mathrm{}(t,p)\mathrm{}$ reactions have been measured with 17 MeV tritons on enriched and natural Pt targets. The level structure of ${}_{}{}^{200}{}_{}{}^{}\mathrm{Pt}$ is probed for the first time, and several new excited ${\mathrm{O}}^{+}$ states have been identified in ${}_{}{}^{196,198,200}{}_{}{}^{}\mathrm{Pt}$. Systematics in level structure of ${}_{}{}^{192-200}{}_{}{}^{}\mathrm{Pt}$ are fairly constant, although there is evidence that ${}_{}{}^{198,200}{}_{}{}^{}\mathrm{Pt}$ are becoming more vibrational in structure, with the $\gamma$-unstable shape of the lighter Pt nuclides becoming more oblate-like. Systematics of $L=4\mathrm{}$ strengths are considered and can be qualitatively understood. The ($t,p$) strengths measured in the present study are combined with earlier $\mathrm{Pt}\mathrm{}(p,t)\mathrm{}$ and $\mathrm{Os}\mathrm{}(t,p)\mathrm{}$ measurements and compared with the systematics of two-neutron transfer strengths predicted by the interacting boson approximation, schematic, boson expansion, and pairing vibration models.

NUCLEAR REACTIONS ${}_{}{}^{194,196,198}{}_{}{}^{}\mathrm{Pt}\mathrm{}(t,p)\mathrm{}$, $E=17\mathrm{}$ MeV; enriched targets; measured energy levels, $\sigma \left(\theta \right)$ in ${}_{}{}^{196,198,200}{}_{}{}^{}\mathrm{Pt}$; DWBA.

NUCLEAR STRUCTURE $L=4\mathrm{}$ transitions, interacting boson approximation model, schematic model, boson expansion technique, pairing vibration model.

• Received 10 October 1980

DOI:https://doi.org/10.1103/PhysRevC.23.1453