Pt194,196,198(p,t) reactions at 35 MeV

Abstract

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\ifmmode^\circ\else\textdegree\fi{} to 60\ifmmode^\circ\else\textdegree\fi{} and the results were compared with zero-range distored wave Born approximation calculations. Several new ${J}^{\ensuremath{\pi}}$ 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\ifmmode^\circ\else\textdegree\fi{} 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 $^{198}\mathrm{Pt}$($p$,$t$), ${E}_{p}=35$ MeV; measured $\ensuremath{\sigma}({E}_{t},\ensuremath{\theta})$; deduced energies, ${J}^{\ensuremath{\pi}}$, and strengths; DWBA calculations, comparison with experiment; enhancement factors. Enriched targets, 7 keV resolution (plates); interacting boson approximation model.