Physical Sciences and Mathematics Commons^™

An Account Of Measurements Of The Mean Range Of Polonium-210 Alpha Particles In Liquid Water, Clyde Eugene Moss Jr.

Master's Theses

A comprehensive account of seven previous measurements of the mean range of Polonum-210 alpha particles in liquid water is presented. Suggestions for obtaining more accurate range measurements are made. The importance of the mean range value to radiobiology is mentioned.

Metrology--An Experiment Where Industry And Education Meet, R. B. Hastings

Journal of the Minnesota Academy of Science

This paper describes a project in which students worked in close cooperation with both the physics department of Macalester College and the gage block laboratory of the Continental Machine Company, manufacturers of ,precision gage blocks. Brief descriptions, including drawings, are given of both the interferometer and the constant temperature laboratory in which all measurements were taken. This constant temperature laboratory is set with precision at those two temperatures between which the average coefficient of linear expansion of a gage block is to be determined. Many such readings were taken and computations of the coefficient of expansion were made. Comparison of …

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].

Spectrographic Study Of The Afterglow Of Mercury, Edward E. Stepp, Richard A. Anderson

Physics Faculty Research & Creative Works

The short duration afterglow of 14 Hg lines was examined, at temperatures of 150°, 200°, 250°, and 300°F, in a cell that had been excited by an rf source. All of the lines exhibited a smooth exponential decay at the lowest temperature. At some temperature above 150°F, however, all of the lines, except the 2537- and 4079- Å lines, exhibited an enhancement of intensity in the time region between 50 and 100 µsec. At the highest temperature all of the lines originating from levels at an energy of 8.84 eV or above, except those originating from the 6¹D …

Measurement Of N₂X¹[Sigma]⁺G Rotational And Vibrational Temperatures Over A 300⁰ K To 1100⁰ K Range Using A High-Energy Electron Beam, William Winslow Hunter

Dissertations, Theses, and Masters Projects

No abstract provided.

Derivation Of The Diffusion Equation And A Revision Of Matsuda's Theory For Polarography, W. Patrick Rahilly

Electronic Theses and Dissertations

Many theories have been proposed to yield a current-time relationship in Polarography. The most widely accepted is that of Matsuda. He assumes that the electrolyte can be separated into an inhomogeneous region about the mercury drop and a homogeneous region elsewhere. This assumption leads to a first order , nonlinear, ordinary differential equation directly solvable by substitution of a properly chosen series. But the series solution obtained is only a particular solution; for there exists, as one would expect, a family of solutions depending on a contrast of integration. In the literature, derivation of the diffusion equation has never been …

Decay Of Certain Mercury Lines In Argon, Thallium, And Pure Mercury Atmospheres, Edward E. Stepp

Doctoral Dissertations

"Organization of thesis and Hg-A study, The time decay of the intensity of selected mercury lines was examined under three different conditions, Each section of this thesis i s divided into three parts corresponding to these three different conditions, In each section part A concerns the decay of intensity of the 2537, 4079, 4360, and 5462 A mercury lines, following the excitation of the states from which they originate by an Hg-A de discharge, Part B concerns the decay of intensity of 14 mercury lines following the excitation of the originating state of these lines by an intense r-f discharge …

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].

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 …

A Study Of Near Surface Elastic-Anelastic Layers, Charles Allen Aldrich

Doctoral Dissertations

"Wave propagation through layered media is of importance in many disciplines. The near surface layers are of special significance, in that most measurements of waves are made within these layers. The purpose of this investigation was to formulate mathematical models with which to analyze the effects of near surface layering"--Introduction, page 1.

Equation Of State Of Nacl And Its Use As A Pressure Gauge In High-Pressure Research, Daniel L. Decker

Faculty Publications

The pressure as a function of lattice parameter and temperature has been calculated for NaCl over a pressure range of 0 to 500 kbar for temperatures between 0degrees and 1500degrees C. The calculation used the Mie-Gruneisen equation of state with Born-Mayer type repulsion terms between first and second nearest neighbors. The Gruneisen constant was expanded about its value at room temperature and atmospheric pressure; the first coefficient in the expansion being evaluated by forcing the calculated thermal expansion at atmospheric pressure to fit the experimental results of Enck. The two empirical parameters in the repulsion terms were evaluated using the …

Pair Distribution For A Cell-Model Liquid, James M. Phillips

Doctoral Dissertations

"The pair distribution function for a cell-model liquid has been derived by Lund in the form of an integral equation which depends upon the cell-center distribution function and the cell model. From this integral equation an approximate integral equation is obtained by substituting a function, which is linearly dependent upon the molecular pair distribution function and a variable parameter for the cell-center distribution function. This approximate integral equation is solved for the molecular pair distribution and the variable parameter is shown to depend upon the difference between temperature and the critical temperature. Although the exact numerical solution of the molecular …

Fock's Representation For Molecular Orbitals, Tai-Ichi Shibuya

University of the Pacific Theses and Dissertations

V. Fock studied the hydrogen atom problem in momentum space by projecting the space onto a 4-dimensional hyper-sphere. He found that as a consequence of the symmetry of the problem in this space the eigen-functions are the R₄ spherical harmonics and that the eigenvalues are determined only by the principal quantum number n. In this chapter we note that if his method is applied to the 2-dimensional Kepler problem in momentum space, the eigenfunctions are the R₃ spherical harmonics, Y_1m, and the eigenvalues are determined only by the quantum number 1. These facts enable one to …

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 …

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].

Bremsstrahlung Production In Lanthanum Thick Targets, David Neil Ferguson

Dissertations, Theses, and Masters Projects

No abstract provided.

An Investigation Of Current Induced Mass Migration In Solid Metals, Steven Mitchell Kovel

Doctoral Dissertations

"In this investigation of current induced mass transport, the general phenomenological equations will be considered first so as to present a picture of the experimental situation. The theoretical computations are then divided into four sections: (1) the determination of the force on a defect due to electron scattering, (2) a discussion of how the force on the defect might be shared by the surrounding ions, (3) how an external force affects the diffusion frequency of an ion, and (4) what the rate of mass transport is under the influence of an electric field. So as to simplify the discussion and …

A Solution To Einstein's Gravitational Field Equation For A Spherically Symmetrical Static Perfect Fluid, Lionel Donnell Hewett

Doctoral Dissertations

"Given spherical symmetry, Einstein's gravitational field equations are reduced to a single, second order, linear, homogeneous differential equation. The solution of this equation for a homogeneous sphere is identical with Schwarzschild's solution...Values of relative density, interior mass, relative pressure, relative and absolute temperature are obtained as functions of radius, r, and are compared with corresponding values for the homogeneous sphere, and for a model sun"--Abstract, page v.

Thick Target Bremsstrahlung Production In Silicon, Maurice C. Mcgee

Dissertations, Theses, and Masters Projects

No abstract provided.

A Formula For Predicting The Angular Distribution Of Thick Target Bremsstrahlung, William Wayne Scott

Dissertations, Theses, and Masters Projects

No abstract provided.

Angular Distributions Of Conversion Electrons From Oriented Ce137M Nuclei, Richard B. Frankel, D. A. Shirley, N. J. Stone

Physics

The angular distributions of K- and of (L+M)-conversion electrons from oriented Ce^137m nuclei were observed. Precise simultaneous intensity measurements of conversion electrons and γ rays from the same sample provided an accurate, direct determination of the particle parameters b₂ associated with the 255-keV isomeric transition in Ce¹³⁷. The K-electron result, b₂=1.061 (18), is in excellent agreement with a theoretical prediction based on a "point nucleus" model. Techniques and parameters in this experiment, the first of its kind, are discussed. A more careful determination of the temperature dependence of …

Observation Of Autoionization Levels In He By Positive Ion Bombardment, M. Eugene Rudd

M. Eugene Rudd Publications

Certain highly excited energy levels in helium have been observed optically and by inelastic electron scattering, and have been calculated theoretically. Reported here is the observation of these levels by the measurement of the energy spectrum of electrons emitted after bombardment with protons and hydrogen molecular ions. Some of the states show up clearly by this method which are weak or absent in the other techniques. Berry has previously observed autoionization of helium by this method, but his measurements lacked the resolution necessary to identify the states.

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 …

The Atmospheric Neutron Spectrum At High Altitudes, Michael Sydor

Physics & Astronomy ETDs

A measurement of neutron flux in the range 30 -130 Mev at altitudes of 10, 670 feet and 100,000 feet was performed with a directionally sensitive proton recoil detector. The detector consisted of two counters of scintillator plastic which measured dE/dx and energy of proton recoils originating in a third plastic scintillator. Charged particles were eliminated by a guard counter. Energy calibration was performed with charged cosmic ray particles; efficiency and angular sensitivity were calculated. The angular response was checked at 10,670 feet, where a reasonable angular distribution of cosmic ray neutrons could be assumed.

Four balloon flights to 100,000 …

Phase-Space Occupation Of Electron, Proton, And Photon Beams, Robert Katz, Basil Curnutte Jr.

Robert Katz Publications

The intensities of known electron, proton, and photon beams are compared to the intensity of a saturated beam of fermions, providing direct experimental evidence for the boson nature of photons.

A Ti-Hg Collision Cross Section, Edward E. Stepp, Richard A. Anderson

Physics Faculty Research & Creative Works

The lifetime of the 6³P₁ state of Hg was observed as a function of Tl density at two different Hg pressures. From these data it appears that at high Tl densities the lifetime of the 6³P₁ state of Hg is controlled by collisions with Tl atoms. Using this assumption and simple gas kinetic theory, a cross section for these collisions was calculated.

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.

Force-On-The-Wall Calculations For One-Dimensional Dense Gases With Intermolecular Potentials., Thomas Daniel Butler

Physics & Astronomy ETDs

The theoretical study of dense gases with strong intermolecular forces is impeded by lack of sufficient experimental which to compare predictions of the properties. High speed computers can supply this information by calculating the detailed dynamics of molecular assemblages, thereby taking the place of an actual physical experiment. This information supplied by the computers not only can test the validity of existing theories, but also it can indicate directions for possible im­provement in the theoretical approximations.

In order to show the adaptability of computers to this task, this thesis deals with the theoretical and computer-experimental study of the force exerted …

Stabilization Of A Balloon-Borne Package, Gary W. Tomlinson

Physics & Astronomy ETDs

It is desirable in certain applications of balloon-borne systems to stabilize the apparatus against rotation about the vertical axis and against tilting. The method of stabilization which will be discussed in this paper involves the use of a set of three gyroscopes which provide a reaction to any torques which would tend to rotate or tilt the package. A model was constructed which demonstrates the feasibility of this method. If the system is to be used for some type of astronomical measurement it may also be desirable to scan a portion of the sky at a constant rate. A method …