The ${}_{}{}^{194,196,198}{}_{}{}^{}\mathrm{Pt}$($p$,$t$) reactions have been studied at a proton energy of 35 MeV using nuclear emulsion plates and a high-resolution position-sensitive proportional counter. Fifty states were observed in ${}_{}{}^{194}{}_{}{}^{}\mathrm{Pt}$ and ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pt}$ and sixty-four in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Pt}$, many for the first time. Angular distributions were measured for many of these levels from 7° to 60° and the results were compared with zero-range distored wave Born approximation calculations. Several new $J^{\pi }$ assignments were made using distorted wave Born approximation and empirical shapes of transitions to well-known levels in Pt and Pb. No new levels, in particular, no new $0^{+}$ levels, were seen below 1.5 MeV excitation. A new $0^{+}$ level at 1.628 MeV was found in ${}_{}{}^{192}{}_{}{}^{}\mathrm{Pt}$, and new levels tentatively assigned to be $4^{+}$ were seen in all three final nuclei near 1.9 MeV with 15% of the ground state strength at 7° in the ${}_{}{}^{196,198}{}_{}{}^{}\mathrm{Pt}$($p$,$t$) reactions. Enhancement factors were calcualted for simple two-neutron pickup configurations. A comparison is made between experimental ($p$,$t$) strengths and those calculated in the O(6) limit of the interacting boson approximation model for $L=0, 2$ transitions.

NUCLEAR REACTIONS ${}_{}{}^{194}{}_{}{}^{}\mathrm{Pt}$($p$,$t$), ${}_{}{}^{196}{}_{}{}^{}\mathrm{Pt}$($p$,$t$), and ${}_{}{}^{198}{}_{}{}^{}\mathrm{Pt}$($p$,$t$), $E_p=35\mathrm{}$ MeV; measured $\sigma (E_t,\theta )$; deduced energies, $J^{\pi }$, and strengths; DWBA calculations, comparison with experiment; enhancement factors. Enriched targets, 7 keV resolution (plates); interacting boson approximation model.

• Received 6 April 1979

DOI:https://doi.org/10.1103/PhysRevC.20.927