Physical Sciences and Mathematics Commons^™

The Leakage Neutron Spectrum Of A Spherical Critical Assembly Of U233, Larry E. Bobisud

Physics & Astronomy ETDs

In this paper the spectrum of the neutrons escaping from a critical sphere of U²³³ is investigated experimentally and theoretically. The experimental investigation involved exposing a nuclear emulsion to the neutron flux and, after development, examining the details of the proton-recoil tracks visible in the emulsion.

On The Velocity Of Sound In Cubic Crystals, Stuart Fleming Hayes

Physics & Astronomy ETDs

The object of this inquiry is to examine the relation between plane wave sound velocities in cubic crystals and the elastic constants of such crystals. Leading directly into this an extensive treatment of the classical theory of elasticity as it pertains to the cubic system. An application of the results will be made by detailing a means for obtaining the elastic constants of plastic single-crystals from measurements of velocity made on poly crystalline specimens.

The Time Required For Nuclear Fission, William Earn Stein

Physics & Astronomy ETDs

The present work is concerned with the mean lifetime of compound nuclei formed in the fast-neutron-induced-fission process. A new method for the measurement of these lifetimes is proposed. The present method is based on the recoil of the compound nucleus following neutron capture and the secondary electrons emitted by fission fragments. Previous experimental and theoretical work concerning the secondary electron yields for fission fragments and other charged particles are reviewed. The importance of the higher energy electrons, the so-called delta rays, formed in the primary ionization process is considered. The subsequent secondary ionization produced by these delta rays provirles a …

The Energy Spectrum Of Gamma Rays Produced In Interstellar Matter By The Primary Cosmic Rays, Duquesne A. Wolf

Physics & Astronomy ETDs

With the advent of the launching of space exploration in the last decade there has been parallel scientific effort to determine the nature of cosmic radiation found in space.

This theoretical study has the objective of determining the energy spectrum of gamma rays produced in interstellar matter by the primary cosmic rays.

The He3 + T Reactions., Darryl B. Smith

Physics & Astronomy ETDs

The energy distribution of the alpha particles and of protons frim the He3+ t reactions have been measured for 1.9-Mev incident tritons at laboratory angles of 30° for alpha, and both 30° and 90° for protons. Absolute cross selections are obtained. The spectra are discussed in terms of a model which assumes that uncorrelated three-body breakup and several two-stage processes all contribute independently to the cross section. The calculations based on this model are in excellent agreement with the observed spectral shapes. The neutron-proton correlation corresponding to the unbound singlet state of the deuteron is observed. The binding energy of …

Multiple Scattering Of High Energy Electrons In A Cerenkov Counter, John Rehnberg

Physics & Astronomy ETDs

The purpose of this thesis is to present a procedure for calculating the fraction of high energy electrons incident on a Cerenkov counter which are scattered out of the region of detection.

With the assistance of Professor Christopher P. Leavitt of the University of New Mexico, a method of solving the above problem has been established. The method uses the theory of multiple scattering as described by Rossi and Greisen and a numerical integration technique to evaluate the effective or average scattering distribution function for the Cerenkov counter. A relationship is developed which can be programmed on a Bendix G-15 …

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.

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 …

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 …