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Full-Text Articles in Physical Sciences and Mathematics
A Superconducting Compact Hydrogen Maser Resonator, David B. Opie
A Superconducting Compact Hydrogen Maser Resonator, David B. Opie
Dissertations, Theses, and Masters Projects
The discovery of high critical temperature superconductors (HTSC) has raised the temperature at which the greatly reduced surface resistance, characteristic of superconducting materials, may be exploited. For microwave frequencies below 100 GHz, the surface resistance, R{dollar}\sb{lcub}s{rcub}{dollar}, at liquid nitrogen temperatures (77K) of the new HTSC materials is found to be better than copper measured at the same temperature and frequency. Consequently, the miniaturization of passive microwave components will be among the first applications of these new materials. This dissertation details the development, testing and evaluation of a superconducting compact hydrogen maser resonator made from electrophoretic Y{dollar}\sb1Ba\sb2Cu\sb3{dollar}O{dollar}\sb{lcub}7-\delta{rcub}{dollar} (YBCO). Such a resonator …
Photodetachment Of Hydride Ion In Perpendicular Electric And Magnetic Fields, Aaron David Peters
Photodetachment Of Hydride Ion In Perpendicular Electric And Magnetic Fields, Aaron David Peters
Dissertations, Theses, and Masters Projects
A simple analytic formula for the photodetachment cross section of H$\sp{-}$ in perpendicular electric and magnetic fields is obtained. Oscillations in the spectrum are predicted by the formula, and these oscillations are correlated with closed classical orbits. We point out that the quantum mechanical derivation, using a stationary phase approximation, is in complete agreement with the three-dimensional semiclassical solution to the problem.
Nucleon Axial Vector Form Factors And Electromagnetic Transition Amplitudes In Perturbative Qcd, Jennifer L. Poor
Nucleon Axial Vector Form Factors And Electromagnetic Transition Amplitudes In Perturbative Qcd, Jennifer L. Poor
Dissertations, Theses, and Masters Projects
Values for the normal isovector axial vector form factor g$\sb{\rm A}$(Q$\sp2$) are calculated from the leading order perturbative QCD hard scattering amplitude and some previously reported models for the nucleon distribution amplitude, some of which have been derived from QCD sum rules. The values obtained from each of the distribution amplitudes gives a result that is consistent with the data extrapolated to high momentum transfer. The axial vector form factor is around one and one half times the proton's magnetic form factor in all the models which is also in accord with the data. We also calculate the isoscalar axial …
U(1) String Tension, Arthur F. Griesser
U(1) String Tension, Arthur F. Griesser
Dissertations, Theses, and Masters Projects
The long distance force between quarks in the U(1) approximation to quantum chromodynamics is calculated on a home made reduced instruction set computer optimized for that purpose. It is found that previous calculations were in error by as much as 85% due to contamination by the Coulomb interaction. The Coulomb constant, measured for the first time in this work, agrees with analytically obtained values.
Magnetic Field Strength Of Toroidal Plasma Equilibria, David Alan Garren
Magnetic Field Strength Of Toroidal Plasma Equilibria, David Alan Garren
Dissertations, Theses, and Masters Projects
The goal of nuclear fusion research is to confine a deuterium-tritium plasma at a sufficiently high temperature (15 keV) and density (3 $\times$ 10$\sp{20}$ m$\sp{-3}$) for a sufficient length of time (1 sec) to produce net fusion power. One means to attain the required plasma confinement is to embed the plasma within a magnetic field. The global structure of this magnetic field determines the variation of magnetic field strength within the surfaces of constant plasma pressure. This field strength variation in turn determines many of the stability and confinement properties of the plasma. This dissertation gives the first detailed exposition …
Completely Bootstrapped Tokamak, Richard Henry Weening
Completely Bootstrapped Tokamak, Richard Henry Weening
Dissertations, Theses, and Masters Projects
A fundamental requirement for the successful operation of a tokamak is the maintenance of a toroidal electric current within the tokamak plasma itself. Maintaining this internal plasma current can be a very difficult technological problem. In this work, a well-known but non-standard method for maintaining the tokamak current called the bootstrap effect is discussed. The bootstrap effect occurs when a fusion plasma is near thermonuclear conditions, and allows the tokamak to greatly amplify its electric current.;Because the bootstrap effect amplifies but does not create a plasma current, it has long been argued that a completely bootstrapped tokamak is not possible. …
Low-Energy Collisions Of Negative Ions With Atomic Hydrogen, Michael A. Huels
Low-Energy Collisions Of Negative Ions With Atomic Hydrogen, Michael A. Huels
Dissertations, Theses, and Masters Projects
Total cross sections for charge transfer and electron detachment for collisions of a variety of negative ions with atomic hydrogen have been separately determined for laboratory collision energies ranging from about 5 eV to 500 eV. The experiments are performed with an apparatus that utilizes a crossed-beam configuration with a radio-frequency discharge as the source of atomic hydrogen.;For collisions of H{dollar}\sp-{dollar}(D{dollar}\sp-{dollar}) with H the charge transfer cross sections increase monotonically with decreasing energy and display an isotope effect. at the lowest collision energies, the electron detachment cross sections are about one order of magnitude smaller than those for charge transfer; …
Nuclear Magnetic Resonance Studies Of Amorphous Nickel-Zirconium Hydrides, Harris Clarence Hoke Jr.
Nuclear Magnetic Resonance Studies Of Amorphous Nickel-Zirconium Hydrides, Harris Clarence Hoke Jr.
Dissertations, Theses, and Masters Projects
This research deals with one aspect of the scientific field of hydrogen in metals. The study of hydrogen in metals is technologically important for many reasons, among them is the use of hydrogen in metals to store energy. Hydrogen related energy technology is particularly attractive because hydrogen can be extracted from water, our most abundant resource, and can be used without any pollution. Metal hydrides may one day be widely used for automotive propulsion in cars, in batteries, and many other energy conversion devices. Amorphous NiZr is particularly interesting for hydrogen storage because high concentrations of hydrogen can be sorbed …