A (t, p) study of levels in 156Gd, 157Gd, 158Gd and 159Gd

Angular distributions of the 154, 155, 156, 157Gd(t, p) 156, 157, 158, 159Gd reactions have been measured using 17 MeV tritons from the McMaster University tandem Van de Graafi accelerator. The reaction products were analyzed with a magnetic spectrograph and detected with photographic emulsions. Excited members of the ground bands in both even and odd nuclei were populated in multistep processes with magnitudes and angular distributions satisfactorily described in CCBA calculations. Levels populated with L=0 transitions were identified from the angular distributions. The 0+ levels at 1050 keV in 156Gd and 1461 keV in 158Gd which were strongly populated in (p, t), were weakly populated in (t, p) in agreement with a recent α-cluster calculation. The summed L=0 strength was smaller in odd than in even nuclei. An increase in the L=0 strength to excited states towards N=98 was observed.