The 159Tb(t, α)158Gd reaction has been studied using 17 MeV polarized tritons from the Los Alamos Scientific Laboratory Tandem Van de Graaff accelerator. The α -spectra were analyzed with a Q3D magnetic spectrometer. The observed analyzing powers for most of the strong transitions have large magnitudes similar to those observed for (t, α ) studies with neighbouring even-even targets. This is consistent with a Nilsson model description of the two quasiparticle states populated in 158Gd, in which most of the strong transitions would be expected to be dominated by a single j-value. The present results provide strong confirmation of the previously suggested assignments of the 1380 keV (Kπ = 4+) and 1930 keV (Kπ = 1+) band heads as 5 2+ ± 3 2+ configurations. Several rotational members of the Kπ = 1- octupole band were populated via the 5 2-- 3 2+ component of this vibration, and from the observed strengths it is estimated that this two-quasiparticle admixture makes up ∼45% of the octupole vibration. Strong transitions to several levels above 2 MeV excitation are dominated by l = 5, j = 11 2 transfers, and these are ascribed to pickup of a 5 2- proton. The spin 5, 6 and 7 members of the Kπ = 4-, 5 2- + 3 2+ band have been assigned at 2176 keV, 2282 keV and 2418 keV, respectively. Whereas previous studies have shown that the (t, α) reaction with polarized tritons is a very useful specroscopic technique when used with even-even target nuclei, the present results extend the proven effectiveness to cases of odd-mass deformed targets.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear reactions