Single-proton states in149Pm

The150Sm(t,α)149Pm reaction was studied using 17MeV polarized tritons from the tandem Van de Graaff accelerator at the Los Alamos Scientific Laboratory. The alpha particles were analyzed using a Q3D magnetic spectrometer and detected with a helicalcathode position-sensitive counter. The overall resolution was ∼25 keV FWHM. In the present study many of the previous spin assignments have been confirmed, and some ambiguities in earlier studies have been resolved. The important levels at 416 and 751 keV that are strongly populated in the stripping reactions are shown to be 3/2+. Also new fragments of theg7/2 andd3/2 shell model states have been located. The deduced spectroscopic factors are compared to those measured in other promethium isotopes. It was found that the total (t, α) strength of the assigned peaks is stable within 15% for the chain of promethium isotopes ranging from mass number 147 to 153.