LEVEL STRUCTURE OF THE ODD-ODD NUCLEUS (224)(89)AC

The level structure of the odd-odd nucleus Ac-224 has been studied by measuring radiations associated with the alpha-decay of the 22 h P-228 isotope. The Pa-228 activity was produced by the irradiation of Th me tal foils with 45 MeV protons. The Pa fraction was subsequently chemic ally isolated. Alpha singles as well as alpha gamma-, alpha e-, alpha gamma gamma-coincidence measurements were performed with thin sources, and a partial level scheme was deduced for the Ac-224. Although the s pins of the observed levels have not been uniquely determined, the dat a establish positive- and negative-parity bands which exhibit characte ristics of parity doublets. In particular, two bands at 354 and 360 ke V appear to be members of a parity doublet. The similarity in the hind rance factors of alpha-decays to the 354 and 360 keV levels, which hav e opposite parities, indicates that the wavefunctions of the two state s are very similar, which is a signature for octupole deformation.