Relative lifetimes, and the closely related quadrupole moments (Q[subscript]i values), of the six superdeformed (SD) bands in �������Hg and the yrast SD band in �������Hg were determined by a Doppler-shift attenuation method measurement. The experiment was performed using the Gammasphere array and Lawrence Berkeley National Laboratory's 88-inch Cyclotron. The Q[subscript]i values, which are a sensitive probe of the nuclear shape, of all the �������Hg SD bands were found to be similar. This is the first accurate determination of the Q, values of SD bands in an odd-A nucleus in the mass-190 region. Additionally, evidence is presented for an unexpected difference in the Q[subscript]i values of the �������Hg and �������Hg SD bands. There is an indication that the Q[subscript]i value of the �������Hg yrast SD band is approximately 15 percent greater that the Q[subscript]i values of the �������Hg SD bands. The results provide information on the shape-driving effects of orbitals in the mass-190 region and imply that the deformations of bands with identical transition energies are not necessarily the same. / Graduation date: 1997

No description available.

The high-spin states of the nucleus ⁷²Ge were populated via the ⁷°Zn(a,2n)⁷²Ge fusion-evaporation reaction at a beam-energy of 30 MeV. The ')'-decays were observed with the AFRODITE spectrometer array at iThemba LABS (Faure, South Africa). Twenty-seven new transitions, 18 new levels and 2 new bands were added to the ⁷²Ge level scheme, and several corrections were made to t he previously-known level scheme. Transitions were characterised using Directional Correlation from Oriented states (DCO) and polarisation measurements, and spin-parity assignments were made for 7 new levels. Spin and parity were also reassigned to a previously-known structure. One of the new bands was ident ified as part of an octupole-vibrational band. No tetrahedral states were observed in the scheme despite N = 40 and Z = 32 having been identified as tetrahedral magic numbers. The meaning of the new 14⁺ yrast level for the underlying structure of the ground state band is discussed

Thesis (Ph.D.)--University of California, Berkeley, 1963. / "UC-4 Chemistry" -t.p. "TID-4500 (24th Ed.)" -t.p. Includes bibliographical references (p. 76-78).

The N=88 isotones lie on the onset of nuclear deformation and have a complicated nuclear structure. To better understand this region, the nuclear levels of ��������Sm were studied in three different �� decay experiments. De-populating ��-rays were measured using the 8�� spectrometer, an array of 20 Compton suppressed Ge detectors. Levels of ��������Sm were populated in varying degrees by three radioactive sources: ��������Pm (J=1���, Q=3454 keV), ��������[superscript m]Eu (J=0���, Q=2303 keV), and ��������[superscipt g]Eu (J=5���, Q=2261 keV), which were all produced at the 88" cyclotron located at LBNL. Among several changes to the existing level structure were the addition of a 0��� level identified at 1603.24 keV, as well as confirming another questioned 0��� assignment of the 1786.47 keV level. Angular correlation analysis was carried out on many different transitions, allowing for spin assignments and the determination of mixing ratios. The results from these three experiments provide extensive new data, and give a fairly complete picture of nuclear levels below about 2 MeV and J���6. The theoretical interpretation of this particular nucleus is still open to question. The data from these experiments, used in conjunction with other studies of nuclei in this same mass region (which are currently underway), may provide further insight into this transition region. / Graduation date: 2003

Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: J.C. Waddington. Includes bibliographical references (leaves 130-137).

Thesis (Ph.D.)--McMaster University (Canada), 1996. / Source: Dissertation Abstracts International, Volume: 57-10, Section: B, page: 6339. Adviser: J. C. Waddinton.

>Magister Scientiae - MSc / The high-spin states of the nucleus 152Gd have been populated via the 152Sm (α, 4n) 152Gd fusion-evaporation reaction at a beam energy of 45MeV. The emitted γ rays were observed with the AFRODITE spectrometer array. The previously known decay scheme of 152Gd was extended. Directional Correlation from Oriented states of nuclei (DCO) and linear polarization measurements were performed in order to assign spins and parities in the 152Gd decay scheme. An alternative interpretation of the first excited Kπ = 0+ band, previously considered to be a β-vibration is discussed.

The inelastic scattering reaction ¹⁶0+¹²C has been studied in the centre-of-mass energy region from 37.7 MeV to 51.4 MeV, in a search for evidence for a seven-alpha chain state in ²⁸Si. The decay products were detected in coincidence at angular separations around 90° in the centre of mass using two position-sensitive strip detectors. Kinematic reconstruction of the quasi-three body final states yielded the differential cross-sections for the decay channels leading to excited states in ¹²C, ¹⁶0 and ²⁰Ne. The excitation functions measured for the <sup>12 C(0+₂)-¹²C(0+₂)-U+03B1 and 12^C(0₂)-⁸Be-⁸Be final states agree broadly between the three experiments that were performed, but contain no structure. Reaction channels have also been identified leading to the ⁸Be-²⁰Ne* and ¹²C*-<sup>16<sup>0* final states. The cross-sections for the ⁸Be-²⁰Ne* decay channels, with the ²⁰ Ne in its lowest excited states, have been compared with previous measurements and provide good agreement. However, none of the excitation functions for these channels contain any structure. The absence of structure in any of the final states, that were identified in this study, indicates that a ²⁸Si chain state is probably not being observed. The same model, that predicts that the seven-alpha chain state should lie in this excitation region in ²⁸Si, has also been used to assign a six alpha chain structure to a resonance at E_x=46.6 MeV in ²⁴ Mg. These two results are compared, and possible reasons for the absence of evidence for a ²⁸Si chain structure are discussed.

Thesis--University of California, Berkeley, 1960. / "Chemistry General" -t.p. Includes bibliographical references (p. 70-73).