Springer Online Journal Archives 1860-2000
Abstract The42Ca levels at 4,715 and 6,633 keV excitation energy have been investigated using the39 K(α,pγ reaction atE α=14 and 15 MeV. From particle-γ-ray angular correlations the spin assignmentsJ(4,715)=6, 4 andJ(6,633)=8, 6, 4 have been obtained. Lifetime measurements using the Doppler-shift attenuation method yieldedτ (4,715)=120±46 fs andτ(6,633)=52±21 fs. Both levels have positive parity and decay by enhancedE2 transitions. They are interpreted as theJ π=6+ and 8+ members, respectively, of theK π=0+ rotational band which has theE x =1,837, 2,423 and 3,250 keV states as further members. The enhancement of inbandE2 transitions is 50 −16 +35 W.u. (6→4) and 63 W.u. (8→6) respectively. The intrinsic quadrupole moments which have been derived on the basis of the coexistence model, areQ 0=1.13−0.16/+0.37b(8→6) andQ 0=1.36±0.25b(6→4), respectively. TheJ π=10+ member of the rotational band has possibly been observed as a level at 8,856±5 keV excitation energy.
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