Date of Award
Doctor of Philosophy
Leo L. Riedinger
Lawrence W. Townsend, Carrol R. Bingham, Witold Nazarewicz
High-spin states of the nucleus 174Hf were populated using the heavy-ion reactions at the Atlas accelerator facility at the Argonne National Laboratory and the 88" cyclotron facility at the Lawrence Berkeley National Laboratory. The de-exciting [gamma] rays are detected with the GAMMASPHERE spectrometer. In this nucleus, eight superdeformed bands are observed for the first time. Studies on these bands as well as eight bands with normal deformation are performed. The hypothesis for presence of a triaxial shape at high deformation in 174Hf is tested via lifetime measurements of the states of the superdeformed structures. The deduced quadrupole moments of four of these bands are compared with the Ultimate Cranker calculations and an additional search for transitions that depopulate these structures is carried out. Discussion on the possibility that these bands manifest triaxiality in 174Hf is presented. The study of the bands with normal deformation employed an extensive systematics of crossing frequencies, alignments, and Routhians. CSM and TRS calculations are performed and compared with these observables. Quasiparticle configurations for all of the bands with normal deformation are proposed, and B (M1) / B (E2) and B (E1) / B (E2) transition strength ratios are analyzed.
Djongolov, Martin Krassimirov, "Superdeformation and High Spin Spectroscopy Studies on 174Hf. " PhD diss., University of Tennessee, 2006.