Physical Sciences and Mathematics Commons^™

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 …

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 …

The Diffraction Of Polarized Light By A Conducting Straight Edge In The Geometrical Shadow, Richard W. Morris

Physics & Astronomy ETDs

Theory predicts that the diffraction pattern of a conduction straight edge will show deviations from the diffraction pattern of a non-conductor, and further, that these deviations will depend upon the polarization of the incident light. In this experiment the diffraction of polarized, coherent light from a monochromatic source by a metallic straight edge was studied in a region near the edge of the geometrical shadow. Two orientations of the polarization were used: one with the E vector of the polarized light parallel to the diffracting edge, and the other with the E vector perpendicular to the diffracting edge. Three different …

Determination Of The Orientation Of Air-Borne Instrumentation, David G. Miller

Physics & Astronomy ETDs

Air-borne devices have been used as a means of observation and collection of information in meteorology and atmospheric physics for many years. Only in recent years, however, has the increasing use of such devices been made for astronomical observations. A balloon-borne telescope at 80,000 to 100,000 feet, for example, has many advantages: the distortion, absorption and scattering of light by the atmosphere and the dependence on weather conditions, which plagues earthbound observations, are essentially eliminated. It seems apparent that astronomical observation will eventually be able to be made only by air­borne or satellite observatories. The decline in usefulness of the …

Large Angle Scattering Of Polarized Light By A Straight Edge, Theodore S. Fahlen

Physics & Astronomy ETDs

The purpose of this experiment was to observe the light diffracted into the geometrical shadow of a sharp and a blunt metallic straight edge using a polarized, very intense, highly coherent light source. The light source used was a ruby laser, and a Nicol prism was used to linearly polarize the laser light. Two polarizations of the laser beam were used: One with the E vector of the incident beam oriented parallel to the edge of the straight edge, and the other with the E vector oriented perpendicular to the edge. One photomultiplier tube was used to monitor the pulsed …

Phase Changes In Solid Cyclohexanol, William T. Griffith

Physics & Astronomy ETDs

Cyclohexanol is one of a group of organic compounds which exist in a “plastic crystal" solid phase, which is intermediate in its properties between the liquid phase and the solid phases stable at lower temperatures. It has been well established that the odd properties of the plastic crystal phase are due to the relatively unhindered rotation of the molecules about their lattice positions. At temperatures often considerably below the freezing point, these compounds undergo a solid-solid phase transformation in which this rotational freedom is lost. The heats and entropies of transformation at this lower transition point are generally larger than …

Single Crystals Of "Globular Molecules" From The Melt, Charles A. Aeby

Physics & Astronomy ETDs

This thesis is an investigation of the possibility of growing single crystals of dl-camphene, d-camphor, and cyclohexanol. These are organic compounds, characterized by "globular molecules", which form plastic crystals immediately below their melting point. Single crystals were desired in order to study, by ultra-sound techniques, properties pertinent to the evaluation of the elastic constants of these crystals. Primary emphasis was placed on growing crystals of dl-camphene, since it is conveniently handled at room temperatures.

Methods of growth from the melt were chosen because of the relatively fast growth rates, compared to vapor or solution techniques. Secondary considerations were simplicity of …

The Effect Of Cesium Vapor On The Emission Characteristics Of Uranium Carbide At Elevated Pressures, Philip W. Kidd

Physics & Astronomy ETDs

The saturated emission current from uranium carbide in the presence of cesium vapor were measured for four different bath temperatures: 167˚C, 197˚C, 227˚C, and 250˚C (the cesium arrival rates μ_a, in atoms/cm², were 3x10¹⁸, 1x10¹⁹, 3x10¹⁹ and 6x10¹⁹). The measurements were made with a “plasma anode” type tube immersed in a constant temperature oil bath. The design of the tube is shown, and the electronic circuitry is given with an explanation of the method of measurement. The experimental data for “electron emission vs 1000/T” was plotted for the experimental …