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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
A Measurement Of The Neutron Electric Form Factor At Very Large Momentum Transfer Using Polarized Electrons Scattering From A Polarized Helium-3 Target, Aidan Michael Kelleher
A Measurement Of The Neutron Electric Form Factor At Very Large Momentum Transfer Using Polarized Electrons Scattering From A Polarized Helium-3 Target, Aidan Michael Kelleher
Dissertations, Theses, and Masters Projects
Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q2 and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized 3He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. GEn was measured …
Applications Of Pattern Classification To Time-Domain Signals, Crystal Ann Bertoncini
Applications Of Pattern Classification To Time-Domain Signals, Crystal Ann Bertoncini
Dissertations, Theses, and Masters Projects
Many different kinds of physics are used in sensors that produce time-domain signals, such as ultrasonics, acoustics, seismology, and electromagnetics. The waveforms generated by these sensors are used to measure events or detect flaws in applications ranging from industrial to medical and defense-related domains. Interpreting the signals is challenging because of the complicated physics of the interaction of the fields with the materials and structures under study. often the method of interpreting the signal varies by the application, but automatic detection of events in signals is always useful in order to attain results quickly with less human error. One method …
Advancements In Dual-Pump Broadband Cars For Supersonic Combustion Measurements, Sarah Augusta. Tedder
Advancements In Dual-Pump Broadband Cars For Supersonic Combustion Measurements, Sarah Augusta. Tedder
Dissertations, Theses, and Masters Projects
Space- and time-resolved measurements of temperature and species mole fractions of nitrogen, oxygen, and hydrogen were obtained with a dual-pump coherent anti-Stokes Raman spectroscopy (CARS) system in hydrogen-fueled supersonic combustion free jet flows. These measurements were taken to provide time-resolved fluid properties of turbulent supersonic combustion for use in the creation and verification of computational fluid dynamic (CFD) models. CFD models of turbulent supersonic combustion flow currently facilitate the design of air- breathing supersonic combustion ramjet (scramjet) engines. Measurements were made in supersonic axi-symmetric free jets of two scales. First, the measurement system was tested in a laboratory environment using …
Electron Scattering From An Almost Free Neutron In Deuterium, Nathan Kidd Baillie
Electron Scattering From An Almost Free Neutron In Deuterium, Nathan Kidd Baillie
Dissertations, Theses, and Masters Projects
The Barely off-Shell Nucleon Structure (BoNuS) experiment measured electron scattering from neutrons bound in deuterium nuclei at Jefferson Lab's Hall B with the intent of obtaining the ratio Fn2/Fp2 at high Bjorken x. The Fn2 structure function is difficult to obtain due to nature's lack of a free neutron target. Previous experiments have measured inclusive scattering from atomic nuclei, but extracting Fn2 from these data requires knowledge of inclusive scattering from the proton and corrections for nucleon binding and Fermi motion. In BoNuS we restrict our analysis to neutron scattering events tagged by a backward-going low-energy recoil proton. This selects …
Extra Dimensions And Electroweak Symmetry Breaking, Jong Anly Tan
Extra Dimensions And Electroweak Symmetry Breaking, Jong Anly Tan
Dissertations, Theses, and Masters Projects
In anticipation of the Large Hadron Collider (LHC) which is currently scheduled to start operating in September 2009, Particle physicists have developed various models to predict phenomena that may be observed in the LHC data. One of the ideas that have been developed is warped extra dimensions. The S parameter, one of the electroweak precision observables is predicted by experiments to be less than about 0.1. However, most of the models that try to explain the electroweak symmetry breaking without a Higgs Boson have a large S parameter > 0.2.;We study the possibility of reducing the S parameter in a wared …
Hadron Structure From Holographic Qcd, Zainul Abidin
Hadron Structure From Holographic Qcd, Zainul Abidin
Dissertations, Theses, and Masters Projects
The AdS/CFT correspondence relates a strongly coupled gauge theory in four dimensional space-time with a weakly coupled gravity theory in five dimensional space-time. This correspondence provides a way to access the strongly coupled regime of a gauge theory via a perturbative approach in its gravity dual theory. In this dissertation, the gravity dual of Quantum Chromodynamics (QCD) is discussed. The so-called bottom-up approach (AdS/QCD) successfully reproduces the low energy observables at 10-20% accuracy.;An AdS/QCD model with two flavors of quarks is considered, assuming isospin symmetry. Pions and rho mesons masses and decay constants are obtained. We calculate the stress tensor, …
Comparison Of Full-Wave And Ray-Tracing Analysis Of Mode Conversion In Plasmas, Yanli Xiao
Comparison Of Full-Wave And Ray-Tracing Analysis Of Mode Conversion In Plasmas, Yanli Xiao
Dissertations, Theses, and Masters Projects
This dissertation reports on the first direct comparison between the results of ray-based and full-wave calculations for mode conversion in plasma. This study was motivated by the modular method originally developed by Ye and Kaufman to treat a magnetosonic wave crossing a cold minority-ion gyroresonance layer. We start with the cold plasma fluid model and introduce a system of evolution equations for electrons and two ion species: deuterium and hydrogen. We first study this system of equations for uniform plasma by Fourier methods, which gives the dispersion relations. We discuss how the traditional approach---which eliminates all other dynamical variables in …
Quantum Information Dynamics, Jeffrey Yepez
Quantum Information Dynamics, Jeffrey Yepez
Dissertations, Theses, and Masters Projects
Presented is a study of quantum entanglement from the perspective of the theory of quantum information dynamics. We consider pairwise entanglement and present an analytical development using joint ladder operators, the sum of two single-particle fermionic ladder operators. This approach allows us to write down analytical representations of quantum algorithms and to explore quantum entanglement as it is manifested in a system of qubits.;We present a topological representation of quantum logic that views entangled qubit spacetime histories (or qubit world lines) as a generalized braid, referred to as a super-braid. The crossing of world lines may be either classical or …
Optical Control Of Ultrafast Spin -Wave Relaxation By Magnetic Anisotropy In A Ferromagnet, Kevin James Smith
Optical Control Of Ultrafast Spin -Wave Relaxation By Magnetic Anisotropy In A Ferromagnet, Kevin James Smith
Dissertations, Theses, and Masters Projects
This thesis presents an investigation of the damping of spin waves in ferromagnetic Au(3 nm)/Ni(10 nm)/MgO(001) thin films using the time-resolved Magneto-optical Kerr Effect (TR-MOKE) and ferromagnetic resonance (FMR) techniques. In the optical measurements, a 150 fs, 800 nm laser beam pulse is split into pump and probe components. The pump pulse, containing most of the beam energy, thermally excites coherent spin precession. The weaker probe pulse, time-delayed by a variable beam path, captures the magnetization dynamics via the polar MOKE effect, and oscillations are observed as a function of external field amplitude and direction. The extracted precession frequency is …