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Total Absorption Spectroscopy Of Mo-106 And Tc-106, Michael Cooper

Doctoral Dissertations

Total absorption spectroscopy is a method of gamma-ray spectroscopy that has gained prominence in the past several decades, as nuclear data revisions are performed on older nuclear data, which is often incomplete. A strong understanding of underlying nuclear data, particularly fission and beta decay data, is essential for nuclear reactors and nuclear fuel decay heat. This PhD work involves the analysis of fission fragments 106Mo [Mo-106] and 106Tc [Tc-106]. These neutron rich isotopes contribute upwards of 6% of the cumulative fission yield of 241Pu [Pu-241] fission, and 4% of 239Pu [Pu-239] fission. Prior data for these two fission fragments only …

Understanding Liquid Dynamics Using The Van Hove Function From Inelastic Neutron Scattering Measurements, Yadu Krishnan Sarathchandran

Doctoral Dissertations

Liquid state physics remains relatively unexplored compared to solid-state physics, which achieved massive progress over the last century. The theoretical and experimental methodologies used in solid-state physics are not suitable to study the liquid state due to the latter's strong time dependence and the lack of periodicity in structure. The approaches based on phonon dynamics break down when phonons are over-damped and localized in liquids. The microscopic nature of atomic dynamics and many-body interactions leading to liquid state properties such as viscosity and dielectric loss in liquids remain unclear. Inelastic neutron scattering measurements were done to study the microscopic origins …

Measurements Of Fast Alpha Decays In The 100sn Region, Ian Connor Cox

Chancellor’s Honors Program Projects

No abstract provided.

Jet Cross-Sections At 8 Tev With The Alice Experiment., Andrew Castro

Doctoral Dissertations

Hadronic jets are created in the earliest stages of a high energy collision due to a hard interaction between two partons. ALICE (A Large Ion Collider Experiment) is one of the main detectors located at the Large Hadron Collider. By using the ALICE Time Projection Chamber and Electromagnetic Calorimeter inclusive jets can be reconstructed over a wide kinematic range. Measuring jets in proton-proton collisions serves as a baseline measurement for understanding energy loss in the nuclear matter and the processes by which quarks form into hadrons. Inclusive jet cross-sections and their ratios were measured in this thesis using the 8 …

An Investigation Of Students’ Use Of A Computational Science Simulation In An Online High School Physics Class, Joshua M. Rosenberg, Michael A. Lawson

Theory and Practice in Teacher Education Publications and Other Works

Science educators have begun to explore how students have opportunities to not only view and manipulate simulations, but also to analyze the complex sources of data they generate. While scholars have documented the characteristics and the effects of using simulations as a source of data in face-to-face, K-12 classrooms, how simulations can be taken up and used in such a way in fully-online classes is less-explored. In this study, we present results from our initial qualitative investigation of students’ use of a simulation in such a way across three lessons in an online, Advanced Placement high school physics class. In …

Complex Oxide Thin Films From Perovskite To Pyrochlore, Clayton Russell Frederick

Masters Theses

The world of condensed matter physics is a fascinating field. With all of the many different elements to explore, it seems impossible to discover all of their secrets. Nevertheless, a study of two different materials is covered in this work. The first type of materials are the Perovskites; these materials are commonly used in materials research, but still have hidden treasures left for research scientist to explore. The second type of materials are the Pyrochlores. The Pyrochlores are not as widely studied as the Perovskite materials, thus, leaving even more avenues to venture down in the quest to learn the …

Let's Get Physical! Teaching Mathematics Through The Lens Of Physics, Peggy Bertrand Ph.D., Lauren Jeneva Clark Ph.D.

Faculty Publications and Other Works -- Mathematics

In 2017, a professional development project, Let's Get Physical! Teaching Mathematics through the Lens of Physics, was funded by a Tennessee Higher Education Commission (THEC) Improving Teacher Quality (ITQ) grant, and was hosted by the University of Tennessee Department of Mathematics. These proceedings contain physics-based secondary mathematics lessons that guided this project. For example, in one lesson, tracking the behavior of live insects helps students learn about displacement, velocity, geometry, and measurement. In another, dropping coffee filters helps students learn about drag, logarithms, and graphical methods. Lasers and lenses can be used to teach reflection and refraction, and one …

Correction To Luminosity Measurement For The Pixel Luminosity Telescope At Cms, Krishna Thapa

Masters Theses

The search for and detailed study of new particles and forces with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) of CERN is fundamentally dependent on the precise measurement of the rate at which proton-proton collisions produce any particles, the so-called luminosity. Therefore, a new detector, the Pixel Luminosity Telescope (PLT), dedicated to measure the luminosity at high precision was added to the CMS experiment in 2015. It measures the inclusive charged particle production from each collision of proton bunches in the LHC. Additional charged particles which are observed by the instrument but produced from sources …

Fundamental Physics With Cold Neutron Beams, Kyle Brandon Grammer

Doctoral Dissertations

The neutron exhibits rich physics both as a tool for studying materials, particle and nuclear physics, as well as the object of experimental study. The neutron lifetime is an important input to Big Bang Nucleosynthesis models and is currently known only to approximately 0.3\% with the most precise measurements from two different experimental techniques in disagreement by more than 3$\sigma$ [sigma]. Parity violation has been the subject of study since its discovery in 1957. Parity violation experiments provide access to studying the hadronic weak interaction, which is otherwise suppressed by several orders of magnitude below that of the strong interaction. …

Solar Modulation Of The Cosmic Ray Intensity And The Measurement Of The Cerenkov Reemission In Nova’S Liquid Scintillator, Philip James Mason

Doctoral Dissertations

The NOνA (NuMI Off-axis electron neutrino Appearance) experiment is a long baseline neutrino oscillation experiment at Fermi National Accelerator Laboratory. Its purpose is to observe the oscillation of ν_μ (muon neutrino) to ν_e (electron neutrino) and to investigate the neutrino mass hierarchy and CP violation in the neutrino sector. Two detectors have been built for this purpose, a Near Detector 300 feet underground at Fermilab, and a Far Detector, on the surface at Ash River, Minnesota.

The completion of NOνA’s Far Detector in October 2014 enabled not only the recent measurement of neutrino oscillations, but an array of …

Analysis, Prototyping, And Design Of An Ionization Profile Monitor For The Spallation Neutron Source Accumulator Ring, Dirk A. Bartkoski

Doctoral Dissertations

The Spallation Neutron Source (SNS) located in the Oak Ridge National Laboratory is comprised of a 1 GeV linear H^- [H^-] accelerator followed by an accumulator ring that delivers high intensity 1 μs [microsecond] long pulses of 1.5x10¹⁴ [1.5x10^14] protons to a liquid mercury target for neutron production by spallation reaction. With its strict 0.01% total beam loss condition, planned power upgrade, and proposed second target station, SNS ring beam-profile diagnostics capable of monitoring evolving beam conditions during high-power conditions are crucial for efficient operation and improvement. By subjecting ionized electrons created during beam interactions with the residual …

Measurement Of The Prompt Double J/Psi Production Cross Section In Pp Collisions At Sqrt(S) = 7 Tev, Andrew David York

Doctoral Dissertations

The simultaneous production of two J/psi mesons has been significantly observed in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector. The two J/psi mesons are fully reconstructed in their decay to muons. The signal yield is extracted with an extended maximum likelihood fit based on four event variables. A method was developed to correct for detector acceptances and efficiencies based on the measured momenta of the J/psi and their decay muons to maintain the least model dependence possible.

The measurement is performed in an acceptance region defined by the individual J/psi transverse momentum and rapidity. …

Structure And Dynamics Of High Temperature Superconductors, Jennifer Lynn Niedziela

Doctoral Dissertations

High temperature superconductivity in iron based compounds has presented a series of complex problems to condensed matter physics since being discovered in 2008. The stalwart basis of condensed matter physics is the “strength in numbers" aspect of crystalline periodicity. Perfect crystalline periodicity has made possible the reduction of the questions of structural and electronic properties to single dimensions, increasing the tractability of these problems. Nevertheless, modern complex materials stretch these assumptions to their limits, and it is at this point where our work starts. Using neutron and x-ray scattering, we have conducted a series of studies on the structural disorder …

Water Ice Films In Cryogenic Vacuum Chambers, Jesse Michael Labello

Doctoral Dissertations

The space simulation chambers at Arnold Engineering Development Complex (AEDC) allow for the testing and calibration of seeker sensors in cryogenic, high vacuum environments. During operation of these chambers, contaminant films can form on the components in the chamber and disrupt operation. Although these contaminant films can be composed of many molecular species, depending on the species outgassed by warm chamber components and any leaks or virtual leaks (pockets of gas trapped within a vacuum chamber) that may be present, water vapor is most common, and it will be the focus of this dissertation. In this dissertation, some properties of …

Atomically Resolved Stm Studies Of The Perovskite Manganite Thin-Film Surfaces, Kenji Fuchigami

Doctoral Dissertations

Perovskite manganites are complex systems in which the structural, electronic, and magnetic properties are strongly coupled - in many cases, non-linearly. A small change in one property (e.g., structure) can produce a large change in other properties (e.g., the electronic state). Conceptually, creating a surface by cleaving a single crystal or growing a thin film provides a controlled way to disturb the coupled system by breaking the symmetry without changing the stoichiometry, which may lead to completely new physical properties. The emerging surface electronic phases can be further enriched by surface reconstructions which often occur due to bond breaking at …

A Study Of The Mechanics Of Microcantilever Sensors, Adam R. Krause

Doctoral Dissertations

Microcantilever sensors are being studied as a new platform for chemical vapor detection. It has been demonstrated by many groups that they have the potential to detect a wide range of chemicals with high sensitivity. Since these sensors do not offer any intrinsic chemical selectivity, immobilized chemical interfaces coupled with pattern recognition algorithms are often employed. Selectivity based on these chemical coatings often fails due to the lack of orthogonality in the chemical interactions. However, the use of adsorption-induced signals based on physical properties can offer additional complementary information. To successfully employ these versatile sensors, a comprehensive investigation of the …

The Elastic Scattering Of Deuterons On ¹³²Sn In Inverse Kinematics, Ryan W. Kapler

Doctoral Dissertations

Half of the elements heavier then [sic] iron are produced in the rapid neutron capture (r-) process. The final abundances of the r-process are determined not only by masses and beta-decays of nuclei on the path, but also neutron capture reaction rates. The structure of neutron-rich nuclei close to the r-process needs to be further investigated and this can be accomplished using the (d,p) reaction. However, conventional experimental methods do not allow for short-lived exotic neutron-rich nuclei to be probed via a (d,p) reaction, as they cannot be made into a target. Using inverse kinematics and radioactive ion beams (RIB) …

Parity Violation In Polarized Cold Neutron Capture, Robert Stephen Mahurin

Doctoral Dissertations

The longitudinal asymmetry in photons emitted during radiative neutron-proton capture depends cleanly on the neutral current contribution to the weak nucleonnucleon interaction. The NPDGamma experiment is an eort to measure this asymmetry with precision ten parts per billion, which is 10% of its range of predicted values. In 2006 the NPDGamma collaboration acquired its rst production dataset at the Los Alamos Neutron Science Center. A pulsed beam of polarized slow neutrons is incident on a 16 L parahydrogen target; capture photons are observed in current mode in a cylindrical array of CsI scintillators. In this initial experiment, roughly 730 hours …

Anisotropic Electron-Phonon Coupling On A Two-Dimensional Isotropic Fermi Contour [Gamma-Bar] Surface State Of Be(0001), Te-Yu Chien

Doctoral Dissertations

Here, we studied an isotropic, free-electron-like 2D electronic band structure system--the Be(0001) [Gamma-bar] surface state. We revealed that the EPC on Be(0001) is anisotropic. Mass enhancement factors are closely related to the strength of the electron-phonon coupling (EPC). Large values of mass enhancement factors represent a strong EPC. For beryllium, the mass enhancement factors, [lambda], of the surfaces are large when compared with the bulk values. However, the reported values of [lambda] of the surfaces are inconsistent among the values obtained from different experiments or theories. One of the possible reasons is that [lambda] is strongly k -dependent. We did …

Patient-Specific Quality Assurance For Imrt, Michelle Lynn Neeley

Masters Theses

In radiation therapy, QA is an integral part of the IMRT treatment process. This study evaluated two different QA modalities, a heterogeneous RANDO phantom and the MatriXX Detector. The RANDO phantom study evaluated the dosimetric accuracy of a helical TomoTherapy system which resulted in a benchmark being established for dosimetric accuracy in heterogeneous materials. The MatriXX study evaluated the performance of the MatriXX Detector to determine if it could be used as a substitute for radiographic film in rotational IMRT delivery techniques. At least twenty test cases were selected for each study, and treatment plans were created using the Hi-Art …

Nuclear Modification Factor (Ra̲̳A̳̲) In Center Of Mass Energy 200 Gev For Cu + Cu Collisions At Forward Rapidity, Dwayne John

Masters Theses

Relativistic heavy-ion collisions are an integral component in studying the small-scale structure of the universe and a probe for nuclear processes. Measurements are an important part of confirming any theory that plans to accurately describe the fundamental processes of the universe. One such measurement of these interactions is the Nuclear Modification Factor (R[subscript AA]). This thesis presents the measurement of R[subscript AA] as a function of transverse momentum for hadrons in Cu + Cu collisions at forward angles. The experiment was performed with the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) from data recorded in 2005 by …

Magnetoelastic Coupling In A Quantum Spin Ladder, Jessica Lynn White

Masters Theses

In this thesis, I present magnetic and optical property studies of a S = 1/2 Heisenberg antiferromagnetic quantum system. The compound under investigation is a copper halide spin ladder, (2,3-dmpyH)₂CuBr₄. This material is attractive not only because of its rarity as a spin ladder with strong magnetic exchange along the rail, but because copper halides are good model materials for the copper oxide systems. Both temperature and magnetic field were used to tune the system. Magnetization was performed, allowing us to observe the experimental critical fields. These critical fields were in reasonable agreement with the theoretical models we extrapolated from …

Use Of Electronic Science Journals In The Undergraduate Curriculum: An Observational Study, Carol Tenopir, Peiling Wang, Richard Pollard, Yan Zhang, Beverly Simmons

School of Information Sciences -- Faculty Publications and Other Works

Phase 2 of a 2-phase project funded by the NSF- National Science Digital Library Project observed undergraduate and graduate engineering, chemistry, and physics students and faculty while they searched the ScienceDirect e-journals system for scholarly science journal articles for simulated class-related assignments. Think-aloud protocol was used to capture affective and cognitive state information, while online monitoring provided an automatic log of interactions with the system. Pre- and post-search questionnaires and a learning style test provided additional data. Preliminary analysis shows differences in search patterns among undergraduates, graduates, and faculty. All groups used basic search functions the most. Graduate students on …