Physics Commons^™

Recoil Corrected Continuum Shell Model Form Factor Calculations For 4He(E,E’)4He(0+), Jiang Yu

Masters Theses

Charge form factor calculations for the electroexcitation of the ⁴He, 0⁺ state have been performed within the context of the recoil corrected continuum shell model. A pure Os⁴ ground state structure is assumed and full internal coordinate recoil corrections are made. The result is compared with available data. It is demonstrated that the 0+ state may be described in a 1p -1h shell model context. Inclusion of nsOs^-1 ground state correlations is suggested for further research.

The Effects Of Low Doses (1 To 500 Kilograys) Of 100-Kev Electrons On Four Polymers, Cynthia Anne Bradbury

Physics Theses & Dissertations

Commercial films of polyetherimide (PEI), polyetheretherimide (PEEI), polyethylene terephthalate (PET), and polycarbonate (PC) were exposed in vacuum to l 00-keV electron radiation to total absorbed doses of l, l 0, l 00, 300, and 500 kilograys. The concentration of radiation-generated radicals, as measured by electron paramagnetic resonance (EPR), increased by over an order of magnitude in all four polymers. Correspondingly, the intensity of the infrared absorption peaks increased uniformly for all doses. Solubility tests resulted in decreased solubility in all polymers. IR, EPR, and solubility suggest dehydrogenation of the aliphatic C-H and phenyl C-H sites. The data indicated that cross …

Theory Of Alpha-Nucleus Collisions At High Energies, Francis A. Cucinotta

Physics Theses & Dissertations

The interaction of high energy alpha particles with atomic nuclei is considered using multiple scattering theories. Semi-classical solutions to coupled-channel equations derived from Watson's form of the nucleus-nucleus multiple scattering series are shown to be equivalent to the Glauber multiple scattering series. Second-order solutions for the elastic amplitude are developed and used to study the effects of short-range correlations in nuclear scattering. The Jastrow method is used to model the two-particle density for ⁴He and to construct one and two particle form factors. Excellent agreement with experimental data for angular distributions, and total and reaction cross sections is found. …

The Relationship Of Pore Volume And Pore Size Distribution To The Development Of Gloss And Scattering Coefficient, John A. Cook

Masters Theses

This study describes in a quantitative manner the relationships between coating structure and optical properties. Gloss, scattering coefficient and void volume were measured after applying different blends of polystyrene spheres to mylar film. Each coating was modeled using large spherical particles of the same size ratios to measure pore size distribution. The coating structure followed well with theoretical packing characteristics of spheres. Optical properties were related to changes in coating structure. Scattering coefficient and gloss correlated better with pore size distribution than particle size. Gloss increased when total void volume was reduced, while the scattering coefficient decreased.

Single-Electron Capture And Loss Cross Sections Vs. Target Z For 1 Mev/U Oxygen Ions Incident On Gases, Scott Avery Boman

Masters Theses

Cross sections for 1 MeV/u oxygen projectile ions which have gained or lost an electron after passing through a gas target were measured as a function of target Z for several incident projectile charge states. The targets used were D_2, He, Ne, Ar and Kr, and the projectiles had charges of 5+, 6+, 7+ and 8+.

The electron capture measurements are generally in reasonable agreement with existing theoretical and empirical scaling rules. The electron loss cross sections differ appreciably from predictions of the PWBA, particularly for the heaviest targets studied. Empirical scaling relationships are derived for the present capture …

Thermodynamics Analysis Of Refrigeration, Joe Lam

Undergraduate Honors Capstone Projects

In this term paper, I will look indepth at refrigeration. Refrigeration is a rather long and complex topic. Therefore, I will only discuss it as detail as conditions permit. As for the parts where minute details required, I will refer you to the selected references. In discussing refrigeration, I will first look at the Carnot cycle as a fundamental issue for refrigeration.

A Study Of An Integral Equations For Computing Radial Distribution Functions, Noraini Ismail

Masters Theses

A two parameter integral equation, equation T is studied to compute radial distribution functions for a classical fluid whose single component particles interact pairwise according to a square-well potential function. A computer program originally written for a DEC 10 was modified to run on a DEC VAX. At the same time, modifications were made to take advantage of the faster VAX and to reduce the time an operator must spend to get a solution to the integral equation. Solutions were obtained for several densities, temperatures, and parameter values. Temperatures ranged from a high temperature gas to near critical temperatures. Accurate …

A Lagrangian For A System Of Two Dyons, Rainer Georg Thierauf

Dissertations and Theses

Maxwell's equations for the electromagnetic field are symmetrized by introducing magnetic charges into the formalism of electrodynamics. The symmetrized equations are solved for the fields and potentials of point particles. Those potentials, some of which are found to be singular along a line, are used to formulate the Lagrangian for a system of two dyons (particles with both electric and magnetic charge). The equations of motion are derived from the Lagrangian. It is shown that the dimensionality constants k and k * , which we r e introduced to define the units of the electromagnetic fields, have to be equal …

The Measurement Of Strong Interaction Effects In High-Z Sigma Hyperonic Atoms, William Clarke Phillips

Dissertations, Theses, and Masters Projects

Strong-interaction effects have been observed in the X-ray spectra of atoms formed with {dollar}\Sigma\sp-{dollar} in lead and tungsten.;In the experiment, performed at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, negative kaons were brought to rest in a novel laminar target consisting of thin sheets of high-Z material in a liquid hydrogen bath. The geometry of the target was designed to optimize the production of high-Z {dollar}\Sigma\sp-{dollar} atoms and the detection of their subsequent de-excitation X rays. A method of identifying the energetic {dollar}\pi\sp+{dollar} from the production reaction K{dollar}\sp-{dollar}+ p {dollar}\to\Sigma\sp- +\pi\sp+{dollar} resulted in a factor of 15 improvement in …

A Fractal Analysis Of Diffusion Limited Aggregation, Cliff Myers

Dissertations and Theses

A modified Witten-Sander algorithm was devised for the diffusion-limited aggregation process. The simulation and analysis were performed on a personal computer. The fractal dimension was determined by using various forms of a two-point density correlation function and by the radius of gyration. The results of computing the correlation function with square and circular windows were analyzed. The correlation function was further modified to include the edge from analysis and those results were compared to the fractal dimensions obtained from the whole aggregate. The fractal dimensions of 1.67 ± .01 and 1.75 ± .08 agree with the accepted values. Animation of …

Statistically Constrained Decimation Of A Turbulence Model, Timothy Joe Williams

Dissertations, Theses, and Masters Projects

The constrained decimation scheme (CDS) is applied to a turbulence model. The CDS is a statistical turbulence theory formulated in 1985 by Robert Kraichnan; it seeks to correctly describe the statistical behavior of a system using only a small sample of the actual dynamics. The full set of dynamical quantities is partitioned into groups, within each of which the statistical properties must be uniform. Each statistical symmetry group is then decimated down to a small sample set of explicit dynamics. The statistical effects of the implicit dynamics outside the sample set are modelled by stochastic forces.;These forces are not totally …