Digital Commons Network^™

Rapid Calculation Of Electron Scattering Factors, Jerry Peacher, John G. Wills

Physics Faculty Research & Creative Works

The phase amplitude method is used to reduce the radial Schrödinger equation to two separate differential equations, one for the phase and one for the amplitude. These functions are both smooth as opposed to the rapidly oscillating solution of the radial Schrödinger equation for electron energies in the kilovolt range. The partial-wave phase shifts were obtained rapidly by integrating the differential equations for the phase and amplitude numerically. Hartree-Fock and Thomas-Fermi-Dirac fields were used in the calculation. Results for argon and uranium are given in order to compare with previous results. It was found that the WKBJ approximation to the …

Single And Multiple Pion Production In Π⁺N And Π‾P Interactions At 1.7 Gev/C, William J. Fickinger, D. K. Robinson

Faculty Scholarship

Meson production in π-p and π+n interactions at 1.7 GeV/c has been studied in two bubble-chamber exposures. Combined results are presented with emphasis on single-pion production (4300 events) which is dominated by the formation of the ρ0 meson in peripheral interactions, and on double-pion production (1100 events) which shows strong formation of the ω meson. These data are compared with the predictions of particle-exchange models, including absorption, and the effects of competing channels are discussed. Evidence for a two-pion decay mode of the ω is examined quantitatively. Processes with higher meson multiplicities are described.

The Alignment Procedure Of A Two Crystal Spectrometer, Jay W. Phippen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

For the sake of completeness, it was felt that a brief resume' of x-ray scattering theory as it affects the alignment procedure of a two crystal spectrometer would be beneficial.

X-ray diffraction from a single crystal slab.

W. L. Bragg (1912) tried the experiment of reflecting a beam of x-rays from the cleavage surface of a crystal and found on the photo-graphic plate a spot at the angle of reflection. He then replaced the photo graphic plate with an ionization chamber which he mounted so that it could be rotated about the axis upon which the reflecting crystal is …

A Calorimetric Study Of The Effects Of Surface Energy In A Type Ii Superconductor, Robert Rex Rice

Doctoral Dissertations

"A calorimetric study of the effects of the interphase surface free energy has been conducted on ellipsoidal samples of first and second kind superconductors. The measurements were performed using a specially designed magnetization calorimeter by two different techniques. The measurements were made on lead, tin, lead-4at%thallium, and tin-6at% indium. The results confirm the existence and experted sign of the surface energy in a well annealed lead-4at%thallium sample, and indicate that the interphase surface energy in lead and tin is too small to be directly detected by this method. The measured latent heats of transition of lead and tin agree well …

A Study Of The Molecular Emission And Of The Life Times Of The Metastable States In The Afterglow Spectrum Of A Mercury Discharge, Bruce M. Whitcomb

Masters Theses

"Two methods of studying the spectrum in the early afterglow of a pure mercury sample are discussed. Using a time-sampling technique, information about the intensity of the spectrum as a function of time in the afterglow can be obtained. The intensities of two molecular bands, centered at 3350A and 4850A, are studied. The method of formation of the diatomic mercury molecule and the emission of radiation in the two bands are shown to be density dependent. Mechanisms are presented which explain both the molecular formation and the radiation in the two bands. In an absorption study, the half-lives of the …

Effect Of Environmental Hydrogen Pressure On The Hydrogen Yield From X‐Irradiated Polyethylenes, Otto H. Hill, R. Pat Lightfoot

Physics Faculty Research & Creative Works

An experimental assembly incorporating a capacitance‐type, differential pressure transducer, which provides resolutions of 3 x 10−4 torr at pressures extending to 30 torr, has been employed to monitor the effect of hydrogen environmental pressure on the hydrogen yield from x‐irradiated polyethylene's. Contrary to the observations of previous investigators, the hydrogen yield is found to be independent of hydrogen environmental pressures extending over the critical range up to at least 30 torr. It is demonstrated that neglecting the temperature and density gradients inherent in closed‐volume irradiation assemblies employing cryogenic traps to separate liberated gases into condensable and non condensable fractions may …

Ferroelectric Properties Of Pbzro₃-Bifeo₃ Solid Solutions, Robert Gerson, Pen-Chu Chou, William Joseph James

Physics Faculty Research & Creative Works

Solid solutions of BiFeO and PbZrO₃ were investigated for crystallographic and dielectric properties. A new pseudocubic perovskite phase was found, which has been tentatively indexed as orthorhombic with the same unit cell as PbZrO₃ but with dielectric properties characteristic of a ferroelectric substance. The Curie point in this series of solid solutions has a minimum of about 155°C at a composition of about (PbZrO₃)_0.80 (BiFeO₃)_0.20, which at room temperature lies on the boundary between the orthorhombic antiferroelectric and the pseudocubic ferroelectric phases. This composition has a relative dielectric constant of 800 …

Magnetic Properties Of The Bifeo₃-Pbtio₃-Pbzro₃ Ternary System, James Ivan Latham

Doctoral Dissertations

"The magnetic susceptibility and spontaneous magnetic moment of the perovskitic, polycrystalline solid solutions of BiFeO₃ with PbTiO₃, PbZrO₃, and [50PbZrO₃·50PbTiO₃] were determined using the Faraday method. Pure BiFeO₃ has a G-type antiferromagnetic structure. Although the perovskite BiFeO₃ exhibits a sharp peak in the susceptibility at the Néel temperature, it does not possess a spontaneous magnetic moment. The solid solutions investigated possessed a spontaneous magnetic moment throughout the multiple cell rhombohedral region of the BiFeO₃-PbTiO₃-PbZrO₃ ternary phase diagram, which extends from pure BiFeO₃ to …

High Frequency Ferroelectric Properties Of The Bifeo₃-Pbtio₃-Pbzro₃ Ternary System, Robert Travis Smith

Doctoral Dissertations

"High temperature dielectric measurements have been performed on the ferroelectric and antiferroelectric perovskitic polycrystalline solid solutions in the BiFeO₃-PbTiO₃-PbZrO₃ ternary system. The data were taken in the UHF frequency range with the use of a slotted line and specially constructed sample holder capable of operation at temperatures in excess of 800°C.

The Curie points have been found to occur at progressively higher temperatures with the increase of BiFeO₃ content in the solutions except in phase transition regions where minima can occur. The dielectric constants at the Curie temperatures have been found to decrease with …

Optical And Electron-Paramagnetic Resonance Studies Of Sodium-Fluoride, Ronald Allen Andrews

Wayne State University Dissertations

No abstract provided.

Coulomb Excitation Of The Ytterbium Isotopes., John M. Palms

Physics & Astronomy ETDs

Coulomb excitation studies have been performed on the ytterbium isotopes 171, 172, 173, 174, and 176 using oxygen ions having energies up to 55 MeV. Resulting de-excitation gamma rays have been observed in particle coincidence with a NaI(Tl) detector and as single spectra with a Ge(Li) detector. The ground state rotational bands of the Yb171 and Yb173 isotopes have been excited to the 13/2- level. The 13/2- and 11/2-levels of both nuclei have not been reported before. In addition to the transitions from the ground state band, gamma rays were observed from Yb171 and Yb173 coming from other bands. A …

Measurements Of Continuous X-Ray Spectra With A Scintillation Spectrometer, Ellery Strom

Physics & Astronomy ETDs

Scintillation spectrometer measurements were made of the x-ray spectra produced by a constant-potential x-ray unit operating at 100, 150, 200, 250, and 300 kV. An attempt was made to measure the absolute intensity as well as the spectral distribution. In order to reduce the counting rate to a measureable level, it was necessary to place the thallium-activated sodium-iodide detector 50 meters from the target. Since the air attenuation was quite large, measurements were made both in air and in helium. In order to contain the helium, an Orangeburg pipe was employed, and its effect on the spectra was determined by …

Simultaneous Flow Of Heat And Water In Plant Tissue, Gaylon Sanford Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although biological phenomena may be partially described in a general way without the use of mathematics and physics, the experimental results may be more meaningful if they are analyzed on the basis of physical and mathematical laws. The complexity of biological systems has made the application to them of mathematics and physics rather difficult, and only recently has much progress been made. Although it has yet been possible to describe only a few simple biological systems by actual equations, a great deal of qualitative information may be obtained by applying physics and mathematics. Russell (1960, p. 439) said

In principle …

Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds. The application of herbicides has thus become a regular agricultural and ecological practice.

Ferromagnetic Metals In High Magnetic Fields, A. J. Freeman, N. A. Blum, S. Foner, Richard B. Frankel, E. J. Mcniff, Jr.

Physics

High‐field susceptibility results are presented for Mössbauer measurements on iron at low temperatures in fields up to 135 kOe and magnetization measurements on iron and nickel single crystals in fields up to 148 kOe with vibrating sample magnetometers. The Mössbauer measurements give the hyperfine field H_n= H_int− (H₀−H_DM)+ΔH, where H_int is the hyperfine field at zero applied field, H₀ is the applied field, H_DM is the demagnetizing field, and ΔH is a term which would reflect a change in the magnetization at high field, …

Isomer-Shift Measurement In W182, S. G. Cohen, N. A. Blum, Y. W. Chow, Richard B. Frankel, L. Grodzins

Physics

No abstract provided.

Diffusion Of The Chlorine Ion In Potassium Chloride , Robert Fuller

Robert G. Fuller Publications

The diffusion coefficient of the chlorine ion was measured in pure single crystals of potassium chloride and in crystals containing mole fractions of strontium chloride between 2.1 x 10^-5 and 4.69 x 10^-4. The results were consistent with the assumption that both anion vacancies and vacancy pairs contribute to the diffusion of the chlorine ion. The diffusion coefficient of the chlorine ion in pure potassium chloride was well represented by the equation D=61 exp (-2.12±0.05 eV/kT) cm²/sec from 560 to 760 °C. The anion-vacancy contribution to the chlorine-ion diffusion coefficient in pure …

Electron Energy Spectrum From Ar+-Ar And H+-Ar Collisions, M. Eugene Rudd, T. Jorgensen Jr., D. J. Volz

M. Eugene Rudd Publications

Absolute differential cross sections have been measured for the ejection of electrons of various energies at 160° by argon ions and protons striking argon gas as a target. The observed energy spectrum consists of a number of "lines" or peaks superimposed on a continuous spectrum. The fine-structure regions occur below 20 eV and from about 120 to 220 eV for both projectiles. A number of lines are identified with auto-ionization transitions from neutral states and with Auger transitions from one- and two-vacancy states. With argon ions each peak has a "Doppler"-shifted counterpart due to electrons emitted from the moving particles. …

Calculated Cohesive Energy Of The Ordered Copper-Gold Alloy Cu Au I, Richard W. Hannum

Doctoral Dissertations

"The ordered alloy CuAu is the fifty atomic per cent alloy in the copper-gold system. It was observed by Johansson and Linde(1) and was one of the first ordered alloys to be studied by x-ray diffraction methods(Z, 3). Two ordered superlattices of CuAu are observed. CuAu I exists below 380° C and has a tetragonal structure which is a slight distortion of the face- centered cubic. It is very highly ordered, with all copper and all gold atoms in alternate (002) planes, as shown in Figure 2. CuAu II, which exists between 380° and 415° C, is orthorhombic in structure(4) …

The Faraday Rotation And Dispersive Doppler Effects In The Ionosphere At Oblique Incidence, Charles Roland Baugher Ii

Masters Theses

"Integral equations for the isotropic and anisotropic ray path of a radio wave propagating through the ionosphere are developed. These equations assume a spherically stratisfied ionosphere and are equivalent to a detailed ray-tracing process. A method is devised to utilize these equations in the evaluation of combined Faraday rotation and dispersive Doppler data from earth satellites for subionospheric electron content. The method, which corrects for horizontal ionospheric gradients, is applied to data from the Explorer 22 satellite and some preliminary results are discussed"--Abstract, page ii.

Absolute Soft X-Ray Dosimetry For Radiation Chemistry Studies, Howard Sajon Joyner

Masters Theses

"A homogeneous, variable plate separation ion chamber consisting of a polyethylene body and employing flowing ethylene as the cavity gas has been designed and tested for the specification soft x-ray (<75kV) energy deposition in typical hydrocarbons. The variable plate separation feature provided primary data on the differential specific ionization originating within the cavity gas occupying the effective collector volume which is independent of inherent chamber inhomogeneities associated with the electrically conducting films comprizing the chamber electrodes. These data demonstrated that charged particle equilibrium is established within the first few ten thousandths of an inch in typical solid hydrocarbons irradiated with this class of sources. Comparison of this type of chamber with a fixed plate separation, static cavity gas mode of operation showed that the latter may predict dose rates with inherent errors exceeding 100%. With the quality of electronic readout accessories presently available, the variable plate separation chamber yielded dose rate data exhibiting a probable error of 3.8 percent (plus the unknown uncertainty in the literature data on the energy required to form an ion pair), and an ultimate limiting error of less than 2 percent appears feasible"--Abstract, page ii.

Observation Of Doppler-Shifted Peaks In The Energy Spectrum Of Autoionizatioin Electrons From Ar+ -Ar Collisions, M. Eugene Rudd, T. Jorgensen, Jr., D. J. Volz

M. Eugene Rudd Publications

It is well known that when heavy ions traverse gas, electron pickup into excited states occurs. If the fast excited atom subsequently decays by radiating a photon, the energy of the photon will be Doppler shifted due to the motion of the source. This effect may be used to distinguish the radiation from stationary and moving atoms. For example, this method was used by Meinel to deduce the motion of solar protons streaming downward through the earth's atmosphere.
If instead the moving atom decays by autoionization, the ejected electron should also show a shift in energy analogous to the Doppler …

Analog Plotting System For Recording Energy Spectra Of Low Energy Charged Particles, M. Eugene Rudd

M. Eugene Rudd Publications

During recent measurements of energy spectra of electrons emitted from gases under positive ion bombardment an analyzing and plotting system was developed which has some unique features. Utilizing an electrostatic analyzer, it sweeps over the desired energy range and plots a graph directly in electron volts. With suitable modifications it could also be used for positive ions. Energies from near 0 to about 1000 eV have been plotted but this range could be extended. Usable graphs have been obtained at counting rates as low as 3 counts/sec.
Compensation is provided for fluctuations in the signal due to slow or rapid …

The Construction Of A Multi-Threshold Foil For Fast Flux Measurements, Michael Henry Holkenbrink

Masters Theses

"The construction of a multi-threshold foil for fast neutron flux measurements is investigated. The factors governing the selection of the materials are the energy response of the given reactor, the half-life of the daughter, the prominent gamma ray emitted during decays, the power level of the reactor, the availability of adequate cross section data, and the alloying properties of the composite foil. A ternary system was chosen as a compromise between the difficulty of fabrication and the amount of information gained from one foil. The particular system chosen was In- P- Fe. The threshold reactions of these elements are In¹¹⁵ …

Theory Of The Lunar Photoelectron Atmosphere, Hal Emerson Mccloud Jr.

Doctoral Dissertations

"By considering the mechanics of an electron projected into an arbitrary potential field together with Poisson's equation it is possible to set up a differential equation for the electrostatic potential. The equation may be integrated and the photoelectron density found as a function of height for four approximate models. A simple model based upon monoenergetic photons and monoenergetic electrons ejected vertically upward yields rough estimates of the parameters of interest. Another model takes into account the fact that the photoelectrons are ejected at all angles. A general model takes into account the illumination of the lunar surface by solar (black …

Re-Evaporation Nuclei And Evaporation In A Wilson Cloud Chamber, James G. Smith

Doctoral Dissertations

"Experimental techniques are developed for observing droplet evaporation in the submicroscopic size range. An expansion-compression cloud chamber with an atmosphere of tank helium saturated with water vapor is employed. This work was undertaken with the aim of examining submicroscopic droplet behavior and the existence of re-evaporation nuclei, a form of memory effect.

The theories of evaporation and nucleation on submicroscopic drop residues were re-examined, and alterations which appear to be consistent with the results of this work were incorporated into the evaporation theory.

The observed continually decreasing evaporation rate with diminishing droplet size confirms the existence of re-evaporation nuclei, but …

Dynamics Of Disordered Harmonic Lattices, Daniel N. Payton Iii

Doctoral Dissertations

"Extensive numerical and analytic studies of vibrational spectra, normal modes, thermodynamic properties, and dynamical properties of harmonic systems with varying degrees of substitutional disorder have been made. The effects on observable properties of random mixtures of two or more species of atoms with differing masses and differing couplings to nearest-and next-nearest-neighbors have been investigated. Using the IBM-7030 digital computer, spectra for linear chains of 100,000 atoms have been obtained. Calculations in two and three dimensions have been limited to arrays of approximately 1000 atoms. Varying composition, mass ratio, and order affect the spectra in two and three dimensions in ways …

Diffusional Drop Growth In A Supersaturated Atmosphere, John C. Carstens

Doctoral Dissertations

"The effect which a growing droplet has on the supersaturated atmosphere surrounding it is analyzed by assuming a macroscopic diffusional growth mechanism involving both heat and vapor. The problem is solved, for cloud-chamber conditions, first for very short times assuming a fixed radius, and then for longer times assuming the establishment of "quasi" steady-state conditions. Knowledge of the way in which droplet growth affects supersaturation is important in the evaluation of nucleation rates"--Abstract, page ii.

Phase Shift Analysis Of Protons Elastically Scattered By 016 Near EP = 8.3 Mev, Glenn D. Westin

Masters Theses

Chapter I

Introduction

The study of the resonances in the scattering cross section of the p + O¹⁶ reaction can reveal information regarding the energy levels of the compound nucleus F¹⁷. The analysis is simplified because of the zero spin of the O¹⁶ nucleus. Also, the low binding energy of the proton added to O¹⁶ allows examination of the low-lying energy levels in F¹⁷.¹ The reaction has been intensively investigated at the University of Wisconsin in a series of experiments using an electrostatic accelerator as a source of protons.

The Calculation Of The Cross-Section Of The Interaction Between Two Yang-Mills Fields, Richard A. Starr

Masters Theses

The Problem and Its Background

This thesis presents a study of the interaction between two arbitrary fields, named Yang-Mills fields¹ for their originators. The basic equations for the calculations of the Yang-Mills interaction are due to modern quantum field theory and its specific application to quantum electrodynamics.²

Much useful information can be obtained from the formulation of the dynamical equations for a classical system: for example, the classical description of the electromagnetic field, based on Maxwell's equations, leads to wave concepts. Then using this formalism as a starting point, one can proceed to the quantum theory of free …