States in the N=87 nuclei 149Sm and 151Gd populated by the (d,t) and (3He,α) reactions

The (d, t) and ( 3 He, α) reactions on targets of 150 Sm and 152 Gd have been studied using a magnetic spectrograph and photographic emulsions to analyze and detect the reaction products. The ( 3 He, α) spectra were measured at two angles for each target using 24 MeV beams of 3 He. The 150 Sm(d, t) 149 Sm reaction was studied at 13 angles with 12 MeV deuterons. The 152 Gd(d, t) 151 Gd spectra were recorded at 4 angles with 15 MeV deuterons. The l values for a number of low spin states were determined from the (d, t) angular distributions. The ratios of ( 3 He, α) and (d, t) cross sections were used to obtain l values for several other states. It is possible to explain the observed strength in terms of the spherical shell model although there is fragmentation of the spherical states. One striking feature is the similarity in the structures of the two nuclei. In both 149 Sm and 151 Gd there are high spin i 13/2 states at ~0.85 MeV and h 11/2 states at ~1.25 MeV.