A study of levels in 155Dy using the (d,t) and (3He,) reactions

The (d,t) and ( 3 He, α) reactions on a target of 156 Dy have been used to study the nuclear structure of 155 Dy. Beams of 15 MeV deuterons and 24 MeV 3 He were obtained from the McMaster University FN tandem Van de Graaff accelerator. The reaction products were analyzed with an Enge-type magnetic spectrograph and detected in photographic emulsions. The (d,t) reaction was studied at 15 angles with typical peak widths (FWHM) of ~ 6 keV and ( 3 He,α) exposures were made at 5 angles with peak widths of ~ 18 keV. The (d,t) angular distributions and ratios of the ( 3 He,α) and (d,t) cross sections were used to determine l values for a number of transitions. It is found that the positive parity states can be described in terms of the Nilsson model when Coriolis coupling is included while for the negative parity states only the gross features are well-described this way.