(p148,t)146Gd reaction: Neutron states inGd146

Abstract

We have used the $^{148}(\mathit{p}$,t${)}^{146}$Gd reaction with protons of 34.6 and 24.9 MeV to study levels in $^{146}\mathrm{Gd}$ below ${E}_{x}$=5.6 MeV. The radioactive target material was deposited on the carbon support foil from an isotope separator. Triton spectra were analyzed by a magnetic quadrupole-dipole-dipole-dipole spectrometer (Q3D) at 11 angles between 10\ifmmode^\circ\else\textdegree\fi{} and 60\ifmmode^\circ\else\textdegree\fi{}. By comparing the angular distributions with the results of distorted-wave Born approximation calculations we obtained definitive L-transfer values for 11 excited states, including a strongly populated ${0}^{+}$ state at 4534 keV, and approximate L values for about 50 additional states. A search for members of the two-octupole-phonon quartet of states expected to occur at \ensuremath{\sim}3.2 MeV of excitation (twice the single-phonon energy) revealed no convincing evidence of the ${0}^{+}$ component, but the ${2}^{+}$ component could be one of the four new ${2}^{+}$ states identified in this region. A comparison between the most strongly populated low-lying states of $^{142}\mathrm{Sm}$ in the $^{144}(\mathit{p}$,t) reaction and states in the pairing-vibrational region of $^{146}\mathrm{Gd}$ reveals a possible set of states whose energies and (p,t) cross sections are in reasonable agreement with predictions of the harmonic pairing-vibration model.