Theses and Dissertations

Hazem Abusara

Issuing Body

Mississippi State University

Advisor

Afanasjev, Anatoli V.

Committee Member

Ma, Wenchao

Committee Member

Winger, Jeff A.

Committee Member

Rupak, Gautam

Committee Member

Koshka, Yaroslav

Date of Degree

12-9-2011

Document Type

Dissertation - Open Access

Major

Applied Physics

Degree Name

Doctor of Philosophy

College

College of Arts and Sciences

Department

Department of Physics and Astronomy

Abstract

In this dissertation, covariant density functional theory has been applied to a variety of nuclear phenomena in the ground and excited states of rotating and non-rotating nuclei. It has been applied for the interpretation of excited superdeformed bands in 154Dy using the effective alignmentmethods. The properties of the predicted hyperdeformed nuclei at high spin in the Z = 40−58 region were investigated and the spins at which such configuration become yrast were defined. The moments of inertia, the role of single-particle energies and necking degree of freedom have also been studied. It also predicted that 107Cd is the best nucleus for its observation. The impact of time-odd mean fields (nuclear magnetism NM) in both non-rotating and rotating frame works, on physical observables has been studied. It is shown that nuclear magnetism always provide additional binding to the binding energies of odd-mass nuclei. Time-odd mean fields affect odd-even mass differences. However, the modifications of the strength of pairing correlations required to compensate for their effects are modest. In contrast, time-odd mean fields have a profound effect on the properties of odd-proton nuclei in the vicinity of the proton drip line. Their presence can modify the half-lives of proton emitters and considerably affect the possibilities of their experimental observation. They also have a profound effect on the dynamic and kinematic moments of inertia, particle number, configuration, and rotational frequency dependencies of their impact on the moments of inertia. The effect of NM on the binding energy and moments of inertia weakly depend on the choice of the RMF parametrization. Fission barriers are studied systematically with the allowence for triaxial deformations, in the actinide and superheavy regions. It is shown that covariant density functional theory is able to describe fission barriers, in actinides, on a level of accuracy comparable with nonrelativistic calculations. Triaxiality in the region of the first saddle plays a crucial role in achieving that. However, in the Z = 112 - 120 superheavy nuclei, the inner fission barriers are not affected by triaxiality. General trends of the evolution of inner fission heights are discussed.

URI

https://hdl.handle.net/11668/19572

Comments

Density functionals.||Nuclear structure.||Quantum theory.

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