Physical Sciences and Mathematics Commons^™

Population Of Low-Lying Levels In The One-Neutron Halo Nucleus 11be Via The Neutron Transfer Reaction 10be(D,P), Kyle Thomas Schmitt

Doctoral Dissertations

Historically, measurements of differential cross-sections for the neutron transfer reaction (d, p) on stable targets have been an important tool for extracting spectroscopic information. In particular, it is possible to make orbital angular momentum assignments and extract spectroscopic factors for ground states and excited states by comparing measurements to cross sections calculated for pure single-particle states. In recent years, the advent of rare isotope beams have made it possible to apply this method to increasingly exotic nuclei. As nucleon separation energies decrease along the path to the proton and neutron drip lines, many new reaction channels are opened. Out of …

Analysis Of 26Al + P Elastic And Inelastic Scattering Reactions And Galactic Abundances Of 26Al, Stephen Todd Pittman

Doctoral Dissertations

²⁶Al(p,p)²⁶Al and ²⁶Al(p,p’)²⁶Al^* scattering reactions were performed at the Holifield Radioactive Ion Beam Facility (HRIBF) at the Oak Ridge National Laboratory (ORNL). The purpose of the elastic scattering study was to determine properties of previously uncharacterized ²⁷Si levels above the proton threshold in the energy range E(c.m.) ~ 0.5 - 1.5 MeV and to calculate reaction rates for the ²⁶Al(p,γ[gamma])²⁷Si reaction that destroys ²⁶Al. The inelastic scattering reaction was also evaluated to investigate the reaction that produces the metastable state of ²⁶Al at E(c.m.) = 228 keV, …

Radii And Neutron Correlations Of (6,8)He Within The Gamow Shell Model, Georgios Papadimitriou

Doctoral Dissertations

We study the spatial correlations between halo neutrons in ^6,8He within the complex-energy Gamow Shell Model (GSM). To this end, we calculate the neutron and proton radii, and two-neutron correlations in a large shell model space consisting of the 0p_3/2 resonance and non-resonant p-sd scattering continuum. We use schematic forces and the finite-range Modified Minnesota interaction.
The calculated charge radii, corrected for the core polarization and spin-orbit effects, are compared to the values extracted from measured atomic isotope shifts.
We find that the charge radius of ⁶He primarily depends on the two-neutron separation energy and the shell-model …

Energy Functional For Nuclear Masses, Michael Giovanni Bertolli

Doctoral Dissertations

An energy functional is formulated for mass calculations of nuclei across the nuclear chart with major-shell occupations as the relevant degrees of freedom. The functional is based on Hohenberg-Kohn theory. Motivation for its form comes from both phenomenology and relevant microscopic systems, such as the three-level Lipkin Model. A global fit of the 17-parameter functional to nuclear masses yields a root- mean-square deviation of χ[chi] = 1.31 MeV, on the order of other mass models. The construction of the energy functional includes the development of a systematic method for selecting and testing possible functional terms. Nuclear radii are computed within …

The Beta Decay Of 79,80,81zn And Nuclear Structure Around The N=50 Shell Closure, Stephen William Padgett

Doctoral Dissertations

This dissertation reports on new information in the [beta minus] decay of the neutron-rich nucleus 81Zn, which populates states in its daughter nucleus 81Ga. This includes new [gamma]-ray transitions in the daughter nucleus, 81Ga, as well as a [beta]-delayed neutron branching ratio. This isotope was produced at the Holifield Radioactive Ion Beam Facility of Oak Ridge National Laboratory through the Isotope Separation Online technique. They are fission fragments from proton-induced fission on a uranium carbide target. These fission fragments are ionized and both mass and isotopically separated before arriving at the Low Energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS). The …

Nuclear Modification Factor For Production Of Open Heavy Flavor At Forward Rapidity In Cu+Cu Collisions, Archil Garishvili

Masters Theses

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory with its muon spectrometer has the ability to detect muons over the range of pseudorapidity 1.1 < |eta| < 2.25. Single muon production is an important tool for studying heavy flavor production via semi-leptonic decays of open heavy flavor mesons. Because of their large mass, heavy quarks are produced in earlier stages of heavy ion collisions. Therefore, heavy flavor production can serve as an important probe of the Quark Gluon Plasma, a novel state of matter predicted to be created at RHIC. The measurement of the nuclear modification factor of open heavy flavor at forward rapidity in Cu+Cu collisions at sqrt{s_{NN}}=200 GeV is presented. Measurements of heavy flavor production in p+p collisions at sqrt{s_{NN}}=200 GeV will be also presented.

Baryon Spectrum Analysis Using Dirac's Covariant Constraint Dynamics, Joshua Franklin Whitney

Doctoral Dissertations

We determine the energy spectrum of the baryons by treating each of them as a three-body system with the interacting forces coming from a set of two-body potentials that depend on both the distance between the quarks and the spin and orbital angular momentum coupling terms. We first review constraint dynamics for a relativistic two-body system in order to assemble the necessary two body framework for the three-body problem. We review the different types of covariant two-body interactions involved in constraint dynamics, including vector and scalar, and solve the problem of energy eigenstates using constraint dynamics. We use the Two …

Remote Sensing Of Sediments And Volatiles On The Martian Surface And Terrestrial Analog Sites, Craig James Hardgrove

Doctoral Dissertations

The role of water and volatiles in the solar system is of critical interest in planetary science. Evidence for the past action of water or direct observation of water on a planetary body can indicate the potential to harbor life and is critical to human exploration of the solar system. We study two very different remote sensing techniques that address the issue of identifying water-related processes on the surface of other planetary bodies, and in particular, Mars. The first technique, combined thermal infrared and visible imaging, has been used extensively on Mars for determining the thermal inertia of surface materials. …

A Study Of The Release Properties Of Sn And Sns From An Isol-Type Target/Ion Source System, Ronald Earl Goans

Masters Theses

Radioactive ion beams (RIBs) provide a method for studying the properties of increasingly exotic nuclei. For many nuclei, the intensity of the RIB available in the isotope separation on-line (ISOL) technique is limited by the relatively long delay time in the target/ion source system (TISS). New techniques are needed to decrease this delay time, thereby increasing the intensity of the RIBs available for study.

The sulfide molecular sideband was discovered in 2001 as a way to greatly enhance the quality of Sn beams. Holdup measurements were performed at the Holifield Radioactive Ion Beam Facility (HRIBF) to determine the extent to …