Single-proton states in 151Pm

The 152Sm(t, α)151Pm reaction was studied using 17 MeV polarized tritons from the tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. The α-particles were analyzed using a Q3D magnetic spectrometer and detected with a helical-cathode position-sensitive counter. The overall resolution was ∼ 18 keV FWHM. Measurements of the 150Nd(3He, d)151Pm reaction were made using 24 MeV 3He beams from the McMaster University tandem accelerator. The deuteron spectra were analyzed with a magnetic spectrograph using photographic emulsions for detectors, yielding a resolution of ∼ 13 keV FWHM. By comparing the measured angular distributions of (t, α) and (3He, d) cross sections and (t, α) analyzing powers with DWBA predictions it was possible to assign spins and parities to many levels. The present results confirm earlier assignments of rotational bands based on the low-lying 52+ [413], 52−[532], 32+ [411] and12+ [420] orbitals. In addition, states at higher excitation have now been assigned to the 12+[411] and72+ [404] orbitals, and members of the 32+[422], 52+ [402], 32− [541] and72− [523] bands are tentatively proposed. The spectroscopic strengths can be explained reasonably well by the Nilsson model when pairing and Coriolis mixing effects are included.