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The Determination Of Thermal Neutron Density From The Absolute Measurement Of The Activity Induced In Gold Foils, Munson M. Thorpe

Physics & Astronomy ETDs

The interaction of thermal neutrons with a coin shaped detector is discussed in terms of the reaction rate in an infinite sheet of pure absorber irradiated in a void by an isotropic, Maxwell distribution of thermal neutrons. A coincidence method for the evaluation of the decay rate of the neutron induced activity in gold is examined in detail and utilized to measure the relative specific activity of gold foils exposed to neutrons in the graphite thermal column of the Water Boiler Reactor. The relative specific activity was obtained for 3/4" and 1/4" diameter foils as a function of thickness for …

Calibration Of A Liquid Scintillator With Geiger-Mueller Counters, William F. Hartman

Physics & Astronomy ETDs

It was the purpose of this experiment to examine the difference in the density determinations and, since the Geiger tube threshold is much lower, to calibrate the liquid scintillator so that it is capable to determining the absolute particle density with greater accuracy.

Diffraction Of Spherical Scalar And Vector Waves At Axial Points Of A Circular Aperture And Disk, Keith Leon Mcdonald

Faculty Publications

The following work treats Kottler's saltus problem of diffraction of electromagnetic waves emitted by a Hertzian oscillator source and the analogous Kirchhoff's scalar problem of waves emitted by a point source. The medium is a homogeneous isotropic dielectric. In the vector case a new exact solution of the basic integrals is presented, at axial points only, (a) behind a circular aperture in a "black'' screen, and (b) behind its complementary "black'' disk. The relative time-averaged intensity of energy flow is plotted for the disk only. It is shown that the scalar theory predicts considerably larger values than the electromagnetic theory …

An Experimental Analysis Of The Lateral Distribution Of Cores Of Extensive Air Showers, Carl E. Scheie

Physics & Astronomy ETDs

It is the purpose of this thesis to investigate the lateral distribution of cores of EAS from a central detector. If the experimental results agree with those predicted theoretically, it can be assumed that the method of locating cores is reliable, thus making it possible to study the energy transfer in EAS.

A Telemetric Compass, Paul Nelson Jr.

Physics & Astronomy ETDs

In certain types of experiments involving balloon-borne equipment it is desirable to know how the orientation of the apparatus varies with time. The author has investigated a method of telemetering azimuthal orientation from a balloon to the ground, and has constructed a protoype of a telemetering magnetic compass. The basis of the compass is a rotating-ring magnetometer of the type first described by Nielsen (1) and used by others (2,3,4) for various purposes. The output of this device consists of two a.c. signals, whose relative phase is determined by the orientation of the magnetometer with respect to the external magnetic …

Anisotropy Of The Cosmic-Ray Flux Caused By An Interplanetary Magnetic Field, Ronald R. Harrington

Physics & Astronomy ETDs

The purpose of this study is to investigate the possibility that this diurnal variation in cosmic-ray flux may be due to a general dipole-like magnetic field centered upon the sun.

A Study Of The Elastic Scattering Of 25-Mev He3 Ions From Various Nuclei, Dale D. Armstrong

Physics & Astronomy ETDs

The validity of the assumption of strong absorption as the basis for the description of the interaction of He³ ions and nuclei was not definitely established and probably cannot be established without the application of more sophisticated theories.

Origins Of Shock-Induced Luminescence In Quartz, William P. Brooks

Physics & Astronomy ETDs

Alpha quartz is a piezoelectric material. As such, it will yield voltage under stress. When shocked with high explosive systems, the material is also luminescent. This luminescence is quite intense and can be recorded on normal films at submicrosecond exposure times.

The luminescence appears in various patterns determined both by the explosive system used and by the orientation of the quartz.

Fused quartz exhibits luminescence to a lesser degree. Since fused quartz is not piezoelectric, it is helpful in the determination of the origin of the luminescence in crystalline alpha quartz.

This study of the origin of the luminescence in …

A Liquid Hydrogen Bubble Chamber Designed For Use As A Neutron Spectrometer, Edward R. Flynn

Physics & Astronomy ETDs

A liquid hydrogen bubble chamber for use as a neutron spectrometer has been constructed and operated. The chamber employs 90^o stereography and is expanded by a piston located in the liquid. The construction and operation of the chamber are described. A special measuring microscope for analyzing the data is described along with the associated electronics for digitizing the screws of this device. Reading rates of 60 proton recoils per hour have been obtained and the reading procedure is discussed. Preliminary results from a neutron-proton differential cross section measurement indicates a resolution of 5% may be obtained with 22 Mev …

"The Effects Of Radioactive Fallout And Disarmament", Linus Carl Pauling

Special Collections: Oregon Public Speakers

There is a slight lapse of about 5 seconds where re-recorded overlap didn't quite cover. Recorded on a Berlout 33 stereo recorded using both tracks in one direction.

Development Of A Chemical Dosimeter Readout System, Everett Oscar Richey

Theses

One of the various methods for measuring doses of ionizing radiation is the halogenated hydrocarbon dosimeter, also called the "chlorinated hydrocarbon," or the "water equivalent" dosimeter. These dosimeters have a range from ten to greater than 10^6 roentgens, and the response is essentially independent of energy, dose-rate, and temperature. This dosimeter consists, basically, of triply distilled water saturated with a halogenated hydrocarbon and an acidimetric indicator dye. Chemical chain reactions induces by radiation liberate acid and the amount of acid formed is directly proportional to the dose.

Relations Between Transpiration, Leaf Temperatures, And Some Environmental Factors, Ronald Kay Tew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Transpiration is the loss of water in vapor form from a plant. This is essentially the same process as evaporation except that it is modified by plant structure. Large quantities of water are removed from the soil, transferred through the conducting tissues of the plant, and dissipated into the air each day. As soon as the water is lost to the atmosphere, it becomes unavailable for human use.

A Satellite Ratemeter Circuit, Daniel P. Christman

Physics & Astronomy ETDs

It was proposed that an attempt be made to measure the directional energy of high-energy primary gamma radiations in space. The difficulties of such an effort are readily obvious. To escape the environmental air envelope of the earth and to lessen the interference of secondary radiations, an instrument package would have to placed into a known orbital trajectory.

A Telemetering Inclinometer, Robert G. Geil

Physics & Astronomy ETDs

In present day experiments in Atmospheric Physics, information from the experiment is sometimes telemetered to observers located at positions remote from the apparatus. To obtain data from the stratosphere an instrument package may be sent aloft suspended from balloons. It is often desirable to know the azimuthal orientation of the instrument package.

To achieve this purpose a rotating ring magnetometer has been developed at the University of New Mexico to measure azimuthal orientation using the earth's magnetic field for a reference. This is sufficient for many purposes. However, due to the wind currents the package suspended beneath the balloon may …

Using A Density Gradient Column To Determine Wheat Density, Wendell R. Peters, Robert Katz

Robert Katz Publications

A wheat kernel placed in a density gradient column will sink until it reaches the level where its average density is equal to that of the liquid at that level. Knowing the density of the liquid as a function of height, one can measure accurately the density of the kernel to three decimal places in about 1 to 2 minutes per kernel. Kernel density ranged from a maximum of 1.416 at 7.5% moisture to a minimum of 1.255 g./cm.³ at 18.5% moisture, for the samples tested. Kernels of a homogeneously selected sample of hard spring wheat (Lee) varied in …

Variation Of Sensitized Fluorescence With Penetration Depth Of Incident 2537a Radiation, George Grayson Robinson

Masters Theses

"An investigation of the sensitized fluorescence of a thallium and mercury mixture using a variable depth cell and photomultiplier type of detection is discussed. Data are given to indicate the variation of the intensity of the 3519A thallium line as a function of thallium temperature, as a function of mercury temperature, and as a function of cell depth. Explanations of results require the use of generally accepted ideas concerning energy transfer, emission, and absorption."

Effects Of Surface Roughness On The Intensity Distribution Of Light Reflected From Aluminum Surfaces, Harvey N. Wingfield

Master's Theses

Only over the past few years have investigations of the intensity distribution of the light reflected from materials been attempted. Most of these investigations have been done by personnel at the National Bureau of Standards on matt surfaces, and acid etched black glass. It should be noted that separate investigations in the two fields, the methods of analysis of a surface's topography and the intensity distribution of reflected light from different materials have been and still are being performed. However, most correlations which exist between a surface's topography and its optical effects such as reflectance, intensity, absorption, and transmission are …

Glass-To-Sapphire End Window Seals, Edward E. Stepp, Richard A. Anderson

Physics Faculty Research & Creative Works

SAPPHIRE windows have been used in laboratory devices where radiation from the ultraviolet through the infrared must be transmitted. Sapphire windows have been valuable in chambers which contain the alkali metals, for the alkali metals are known to react with Pyrex 7740 glass and quartz leaving them pitted and darkened. This paper is a report on an improved glass-to-sapphire end window seal.

The Magnetic Pole In The Formulation Of Electricity And Magnetism, Robert Katz

Robert Katz Publications

The use of the magnetic pole in the development of the concepts of electricity and magnetism leads unambiguously to a relativistic formulation of the field vectors which is well within the grasp of the sophomore student. The development is wholly consistent with Maxwell's equations and leads to clear and understandable definitions of the field vectors both in vacuum and in the material medium, as well as to the relations defining the transformations of the field vectors.

A Matrix Formulation Of The Least-Squares Method And Its Application To Nuclear Decay Schemes, Otto Harry Otteson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many people call physics an ''exact science". This may be true depending on our definition of exact. Most dictionaries include as a definition of exact the words "strictly accurate". The average man thinks of an "exact science" as one which yields "strictly accurate'' results. Physics then is exact only to a degree.

A Study Of Duffing's Equation, Charles Kirby Murch

Masters Theses

"The unforced cases of Duffing's equation and the equation of the simple pendulum are considered by imposing certain conditions on a linear partial differential equation. Geometrical arguments are presented which lead to solutions of the special cases considered.

Undetermined functions of integration in the solutions limit their use to the approximation of systems with small non-linearity"--Abstract, page ii.

Neutron Flux Mapping Of The Msm Reactor, Cary Chow-Yuen Chen

Masters Theses

"This investigation presents a mean to determine thermal neutron flux of a reactor by irradiating copper wires inside the fuel elements. The activity recorded after decay correction, is the relative thermal neutron density. Thermal neutron flux is a measure of the neutron density at thermal energy, 0.025 ev.

Gold foils irradiated at National Bureau of Standards were used as the absolute neutron flux calibration standards. The average flux of the reactor with water as the reflector ranges from 7.24 x 10¹⁰ neutrons/cm² - sec. to 7.87 x 10¹⁰ neutrons/cm² - sec. as obtained from the calculations. …

"Invariant Imbedding" And Wave Propagation In Inhomogeneous Media, Crawford J. Maccallum

Physics & Astronomy ETDs

We wish now to address ourselves to that problem which can be described in physical terms as the reflection and transmission of "waves" by and through some sort of "transition region" between two homogeneous media. At this stage we will work strictly within one dimension; later on this severe restriction will be somewhat eased. For simplicity of notation we will for the present give the transition region a finite thickness h; later on we will often allow h to become infinite when the disturbance due to the transition region dies away fast enough with distance.

A Note On K-Commutative Matrices, D. W. Robinson

Faculty Publications

Let A and B be square matrices over a field in which the minimum polynomial of A is completely reducible. It is shown that A is k commutative with respect to B for some non-negative integer k if and only if B commutes with every principal idempotent of A. The proof is brief, simplifying much of the previous study of k-commutative matrices. The result is also used to generalize some well-known theorems on finite matrix commutators that involve a complex matrix and its transposed complex conjugate.

Transverse Mass And Gravitational Mass, Robert Katz

Robert Katz Publications

A problem suggested by Professor Gamow deals with the relationship between the transverse mass and the gravitational mass: A steamroller of mass m moves horizontally, in the +x direction, with velocity v, in a region of space in which there is a gravitational field intensity g vertically downward. Find the weight of the moving steamroller.

Long-Range Particles From Nuclear Fission, Ralph A. Nobles

Physics & Astronomy ETDs

This work is concerned with experimental observations of the long-range particles which are occasionally emitted by fissioning nuclei. These particles are known to be principally alpha particles and are of interest because they are associated with the configuration of the nucleus at the crucial time of scission. Observations were made of the energy spectra of long-range particles by means of a thallium-activated multiple CsI crystal scintillator device.

4th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Abstracts of papers presented at the 4th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 10-11, 1961.

Investigation Of The Platinum-Rich Portion Of The Platinum-Tantalum Phase Diagram, Bob Dean Browning

Theses and Dissertations

The Pt-Ta binary system was investigated at two isotherms;1000°C and 1500°C, and at eleven alloy compositions in the range of 50 to 100 atomic percent platinum. The alloys were examined by x-ray diffraction and metallography. Three intermetallic compounds, Pt₂Ta, Pt₃Ta, and Pt₄Ta were found to exist in this composition range. The Pt₄Ta intermetallic appeared only at the 1500°C isotherm. Platinum dissolved tantalum substitutionally to 90 atomic percent at 1500 °C and to approximately 80 atomic percent at 1000 °C.

Hardness And Moisture Content Of Wheat Kernels, Robert Katz, N. D. Collins, A. B. Cardwell

Robert Katz Publications

The hardness of kernel sections of hard red winter and soft white winter wheat and durum wheat decreased with increasing moisture content. Small variations in hardness with variety and test plot location were detected.

A Calibration Method For Satellite Cerenkov Instrumentals, Robert E. Dekinder Jr.

Physics & Astronomy ETDs

The problem posed for this thesis is one of determining a method of calibrating a photomultiplier tube when it is contained in an orbiting instrumentation package. Since it is planned for the satellite to remain in orbit for about two years, a method to determine drift of the telemetered output versus the selected radiation input would be very desirable. This drift could arise from changes in the power supplied to the system, or by the telemetering or logic circuits changing characteristics from exposure to cosmic radiation. The situation requires that light of constant intensity be produced in the "field of …