Physics Commons^™

Development Of A Method For Measuring Magneto-Optical Rotatory Dispersion, Donald K. Loving

Masters Theses

No abstract provided.

A Study Of An Electric Method To Excite And Detect Acoustic Waves In Solids, John H. Stevens

Masters Theses

"This experiment has demonstrated that it is possible to generate pulses of acoustic waves in an aluminum single crystal by the direct use of the tensile stress associated with an electric field at the surface of a conductor, and it is possible to detect these waves with a biased, capacitive pickup transducer"--Abstract, page ii.

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 …

A Study Of The Afterglow Of An R-F Excited Mercury Discharge, James A. Aubrecht

Masters Theses

"The short duration afterglow of an r-f discharge in mercury has been examined versus ground state mercury atom density and r-f power. The intensity of the 5771, 5462, 4360, 4079, 4047, 3907, 3651/56, 3342, and 3127/32Å atomic mercury lines were observed to decay as a function of time after the shut off of the active discharge. At temperatures below 333⁰K, all atomic lines decayed exponentially, and no molecular emission was observed. From 333⁰K to 423⁰K, the atomic lines were observed to decay rapidly initially, then exhibit an enhancement effect in intensity which was produced by metastable atom collisions, and finally, …

The Mössbauer Effect In Bismuth Ferrate, Bruce A. Banks

Masters Theses

"The magnetic hyperfine structure of the Fe⁵⁷ nuclei in bismuth ferrate was investigated using the Mössbauer effect. A Mössbauer effect spectrometer was built with consideration given to the elimination of vibration and the optimizing of the source, absorber, and detector geometries to produce the largest fractional Mössbauer effect per fractional standard deviation. The internal magnetic field at the Fe nuclei in BiFeO₃ was determined to (482 ± 9) kilooersteds at room temperature"--Abstract, page ii.

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.

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 …

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.

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 …

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.

Nuclear Magnetic Relaxation And Diffusion In Paraffin Oil, David E. Parker

Masters Theses

Introduction

Since the introduction of the spin echoes technique by E. L. Hahn¹ many studies have been made in the determination of the spin relaxation T₂, spin-lattice relaxation T₁, and the diffusion rates in gases, liquids^2-5, and solids^6-10. Hahn's methods were later improved by Carr and Purcell¹¹. The Carr-Purcell method serves as the basic technique for this study.

Several studies have been published on the relaxation and diffusion rates in hydrocarbons¹². These studies have shown:

1. The spin relaxation time T₂, is independent of the …

Operating Characteristics Of A Cloud Chamber Suited For Condensation Measurements, Donald L. Packwood

Masters Theses

"It is the main purpose of this research to investigate the validity of using the adiabatic laws to determine the temperature from the pressure ratio. Some of the effects which might invalidate the use of the adiabatic laws will be studied. Special consideration will be given to the accurate calculation of [gamma]. Carstens' approximate calculation of the heat flow into the chamber due to conduction will be checked. A measurement will be made of how long the chamber remains adiabatic after an expansion when the continuing expansion technique is used. The static temperature gradient throughout the chamber will be measured …

Drop Growth In A Supersaturated Vapor, Roger Buecher

Masters Theses

"Using kinetic theory and the thermodynamics of phase transitions, a method is derived for finding the growth rate and temperature increase of a droplet in water vapor which has been supersaturated by the expansion of a cloud chamber. Calculations are performed for a specific numerical example and compared to other work in this field"--Abstract, page [2].

A Study Of Re-Evaporation Nuclei, Ronald Dawbarn

Masters Theses

"Classical considerations of the evaporation of a homogeneously nucleated droplet in an atmosphere of low humidity, indicates complete evaporation of the drop. Experimental results however, show that there is left behind a residual nucleus that is quite stable. Condensation occurs on these nuclei at comparatively low supersaturations. Using a specially instrumented cloud chamber, experimental procedures are described which attempt to investigate some of the properties of these nuclei. Various possibilities causing this stability are examined and compared to the experimental results obtained"--page [ii].

A Measurement Of Dead Space And Its Effect On The Homogeneous Nucleation Rate Of Water Vapor In Helium, Michael A. Grayson

Masters Theses

"The existence of a "dead space" surrounding each nucleated water droplet is demonstrated and measurements of its rate of development are made. The effects of this "dead space" are considered to be due to both the removal of vapor from the helium-water vapor mixture and the evolution of heat about the drop due to its growth. The results confirm the usefulness of the concept of a "dead space" and provide a means for its measurement with respect to time. Recommendations for further study and a method of correcting for dead space effects is given"--page [i].

An Instrument For The Measurement Of Anelastic Properties Of Glass, Thomas Frederick Miller

Masters Theses

"An inverted torsion pendulum for measuring the internal friction and dynamic shear modulus of glass fibers over an extended temperature range has been constructed and calibrated. The calibration consists of the determination of the moment of inertia. Extraneous damping losses were investigated and primary sources were found to be (1) the suspension thread, (2) the method of securing the fiber and (3) air damping. Anelastic measurements were made on an annealed vitreous silica fiber and a soda-lime-silica fiber"--Abstract, page ii.

A Second Study Of Homogeneous Nucleation Of Water Vapor In Helium, Raymond J. Schmitt

Masters Theses

"Absolute homogeneous nucleation rates in a supersaturated mixture of water vapor and helium are measured using a long sensitive time expansion chamber and a method devised by Kassner and Allard. A pulse technique is employed to produce the nucleation in an effort to suppress disturbing influences of vapor depletion and droplet growth. The time-varying nature of the supersaturation during the nucleation pulse is taken into account by an Integration over the pulse. Observed and theoretically predicted droplet concentrations are related by an assumed nucleation rate law which is adjusted until the total droplet populations predicted by integration of the assumed …

Investigations Of Neutron Collimators And Detector Systems Used In A Neutron-Capture Internal-Conversion Apparatus, William Charles Johnston

Masters Theses

Preface

During the past six decades considerable effort has been devoted to investigating and explaining the phenomena associated with the atomic nucleus. However, many important features of the nucleus still are not understood. Among these are such fundamental aspects as the structural composition of the nucleus, the nature of the forces between nucleons, and several of the basic processes that occur among the nuclear constituents. The goal of nuclear physics is to construct a unified theory which is able to explain all nuclear phenomena.

The experimentalist contributes toward this objective by gathering and classifying extensive amounts of experimental data in …

Angular Correlation Of Co60, Henry Kuhlman

Masters Theses

Chapter I

Introduction

The probability that a radioactive nucleus will emit a gama ray may depend on the angle between the nuclear spin axis and the direction of emission. The radiation pattern of a sample of randomly oriented nuclei is isotropic. An anisotropic pattern may be observed if the nuclear spin axes are aligned.

A Measurement Of The Spin Relaxation Time Of Optically Pumped Rubidium Vapor, Robert Oliver Breault

Masters Theses

Chapter I

The Problem and Atomic Energy Levels

In 1949 Francis Bitter proposed a method for optcally detecting radio frequency resonance. That same year Alfred Kastler, Fcole Normale Superiéure, Paris, France, introduced a technique, which he called "Optical Pumping", of concentrating atoms in some of the Zeeman sublevels of one of the hyperfine state levels of the ground state. These two experiments are the basis of research involving optical methods of atomic orientation and of magnetic resonance.

An Investigation Of The Sensitized Fluorescence Of The Mercury-Sodium And The Cesium-Rubidium Systems., Joseph Edward Hueser

Masters Theses

"The experimental apparatus and techniques used for the study of sensitized fluorescence are discussed. In this study both glass and metal absorption cells were employed. Included also is a discussion of the transitions which 11 occur in the mercury-sodium and the cesium-rubidium systems, which were the two systems investigated. Both photographic and photometric techniques were used as means of detecting the sensitized fluorescence. The actual experimental apparatus used are discussed together with conclusions to be drawn and recommendations to be made from the individual experiments. The purpose of the experiments was to better understand the energy exchange processes in a …

Transverse Spin Relaxation Of Optically Pumped Rubidium., Robert Evans Hufft

Masters Theses

The study of the transverse spin relaxation of rubidium vapor is a continuation of the work done by Kenneth Steinbruegge¹ and that in progress by John Martin² at the University of Missouri at Rolla. The purpose of the experiment is to study the change of intensity of the transmitted pumping light at resonance in the longitudinal direction, and the observation of the high frequency modulation of a second "cross" beam of light perpendicular to the first. Under resonant conditions this "cross" beam will exhibit a phase coherence and a loss of phase coherence when parameters of the experiment …

A Study Of The Effect Of The Crystal Orientation On The Internal Friction Of Magnesium Single Crystals., Robert Ray Nothdurft

Masters Theses

"The method of growing, etching, and cutting magnesium single crystals is described in some detail. Ten single crystals of magnesium of different orientations were prepared and studied. The internal friction and relative Young’s modulus were measured for each specimen as a function of applied stress on a quartz composite oscillator. The effect of the orientation on the strain amplitude independent decrement, the strain amplitude dependent decrement and the ratio of the strain amplitude dependent decrement to the relative Young's modulus is compared to the theory of the pinned dislocation model of Granato and Lücke"--Abstract, p. ii

Aging Of The Dielectric Properties Of Some Perovskite Ceramics, Hector Troche-Maldonado

Masters Theses

"The effect of aging upon the dielectric constant and the dissipation factor were investigated for a number of lead titanate zirconate ceramics of varying composition. The ceramics investigated have a perovskite type structure. The materials chosen all have tetragonal symmetry at room temperature but are close in composition to materials of rhombohedral symmetry.

Empirical relations were determined for each specimen giving the rate of aging of the dielectric constant (K) and loss factor in terms of the frequency (f) and the elapsed time (t). The range of frequency was l kcps to l mcps; the range of elapsed time was …

Construction And Test Of Equipment For Use In Ultrasonic Pulse Echo Studies., Charles Joseph Reinheimer

Masters Theses

"An ultrasonic pulse generator was constructed with a variable pulse width ranging from 4 microseconds to 10 milliseconds and a repetition period varying from 15 milliseconds to 5 seconds. The oscillator had an almost continuous range from 500 kilocycles to 18 megacycles per second.

Its applicability in studies of internal friction of metals was demonstrated with a single crystal aluminum sample"-- Abstract, p. vi

Studies Of An Electrical Method For Generating Ultrasonic Waves, Yung-Yien Huang

Masters Theses

“Ultrasonic waves have proved very valuable in the observation of both the velocity and the absorption coefficient of sound in various media. From the velocity measurements of ultrasonic waves in metals, it is possible to obtain elastic constants, such as the compressibility, and the specific heat. Also, the observed attenuation depends greatly on the type and structure of the material. One of the widely used methods for investigation of the internal losses in solid state physics is the pulse-echo technique. This method is being used almost exclusively in internal friction investigation"--Introduction, page 1.

Longitudinal Spin Relaxation Of Optically Excited Rubidium., John Robert Martin

Masters Theses

"This thesis is intended to be a guide to the theory and experimental procedures of optical pumping in one of its most usual applications. It is also intended to be an extension of the work done here by Steinbruegge¹ in 1963 along with several significant changes and improvements in experimental techniques. A study is made of the optical pumping of rubidium vapor, and results are given stating the most efficient methods with which to produce large populations of optically oriented rubidium atoms, and thereby determine the relaxation properties of a given rubidium system"-- Abstract, p. ii

Determination Of The Fast Flux Of U.M.R. Reactor, Dave Vibhakar Ratilal

Masters Theses

"Measurements of fast flux of University of Missouri at Rolla, Reactor have been made using: (n,p) reactions in Mg²⁷ and Ni⁵⁸ and (n,α) reactions in Al²⁷. The effective activation cross sections at respective threshold energies for various foils have been obtained from AERE and AECL reports and from literature published by various investigators. A RIDL 400 channel analyzer was used for counting"--Abstract, page 1.

The Dielectric Properties Of Thallium Nitrate., Gene E. Gowins

Masters Theses

"The purpose of this research was to investigate the dielectric behavior of thallous nitrate and to determine whether it belongs to space group Pbnm or to Pbn2.

The growing of single crystals of thallous nitrate which are suitable for dielectric measurements is difficult because the crystals are prone to initiate a dendritic growth habit. In the present work single crystals of thallous nitrate were obtained, however, by slow evaporation of an aqueous solution at 55 degrees centigrade. The crystals were plates, not larger than 8 x 8 x 2 mm, whose principal faces were subsequently indentifled as (001) planes. The …

Development Of A Two Channel Counter For Measurement Of Faraday Rotations, Donald R. Flach

Masters Theses

Chapter I

Introduction

The rotation of the plane of polarization of plane polarized light when it passes through a substance in a direction parallel to an applied magnetic field is known as the Faraday effect and was discovered by Michael Faraday in 1845.¹ It was found by experimentation that the amount of rotation of the plane of polarization was represented by the equation:

Θ = VH1 cos A

where H = magnetic field in gauss, 1 = simple path length in centimeters, A is the angle between the magnetic field and the direction of the light, and V is …