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Full-Text Articles in Physical Sciences and Mathematics
20 Polarization, Charles G. Torre
20 Polarization, Charles G. Torre
Foundations of Wave Phenomena
Our final topic in this brief study of electromagnetic waves concerns the phenomenon of polarization, which occurs thanks to the vector nature of the waves. More precisely, the polarization of an electromagnetic plane wave concerns the direction of the electric (and magnetic) vector fields. Let us first give a rough, qualitative motivation for the phenomenon. An electromagnetic plane wave is a traveling sinusoidal disturbance in the electric and magnetic fields. Let us focus on the behavior of the electric field since we can always reconstruct the behavior of the magnetic field from the electric field. Because the electric force on …
Electric Field Induced Hopping Conductivity And Polarization In Hytrel, Steve Hart
Electric Field Induced Hopping Conductivity And Polarization In Hytrel, Steve Hart
Senior Theses and Projects
The focus of my 4900 research project is centered on the conductivity of Hytrel, a complex, newly developed block co-polymer. I first began to study Hytrel during the summer of 2006, as part of the USU College of Science Mini-Grant program1. My general objective was to study the relationship between the resistivity of Hytrel and hopping conductivity. Hopping conductivity is a theory of electron transport for nonconducting solids, originally developed for amorphous semiconductors2,3. The theory will be examined in greater detail later in this document. While studying this relationship last summer, I noticed an unusual phenomenon …
Schroedinger Representation For The Polarized Gowdy Model, Charles G. Torre
Schroedinger Representation For The Polarized Gowdy Model, Charles G. Torre
All Physics Faculty Publications
The polarized T3 Gowdy model is, in a standard gauge, characterized by a point particle degree of freedom and a scalar field degree of freedom obeying a linear field equation on R × S1. The Fock representation of the scalar field has been well studied. We construct the Schrödinger representation for the scalar field at a fixed value of the Gowdy time in terms of square-integrable functions on a space of distributional fields with a Gaussian probability measure. We show that 'typical' field configurations are slightly more singular than square-integrable functions on the circle. For each time the corresponding Schrödinger …
Experimentally Derived Resistivity For Dielectric Samples From The Crres Internal Discharge Monitor, Nelson W. Green, A. Robb Frederickson, John R. Dennison
Experimentally Derived Resistivity For Dielectric Samples From The Crres Internal Discharge Monitor, Nelson W. Green, A. Robb Frederickson, John R. Dennison
All Physics Faculty Publications
Resistivity values were experimentally determined using charge-storage methods for six samples remaining from the construction of the internal discharge monitor flown on the Combined Release and Radiation Effects Satellite (CRRES). Three tests were performed over a period of three to five weeks each in a vacuum of ~5times10-6 torr with an average temperature of ~25degC to simulate a space environment. Samples tested included FR4, polytetrafluoroethylene (PTFE), and alumina with copper electrodes attached to one or more of the sample surfaces. FR4 circuit-board material was found to have a dark-current resistivity of ~1times1018 Omegamiddotcm and a moderately high polarization …
Methods For Resistivity Measurements Related To Spacecraft Charging, John R. Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A. Robb Frederickson
Methods For Resistivity Measurements Related To Spacecraft Charging, John R. Dennison, Jerilyn Brunson, Prasanna Swaminathan, Nelson Green, A. Robb Frederickson
All Physics Faculty Publications
A key parameter in modeling differential spacecraft-charging is the resistivity of insulating materials. This parameter determines how charge will accumulate and redistribute across the spacecraft, as well as the timescale for charge transport and dissipation. American Society for Testing and Materials constant-voltage methods are shown to provide inaccurate resistivity measurements for materials with resistivities greater than ~1017 Omegamiddotcm or with long polarization decay times such as are found in many polymers. These data have been shown to often be inappropriate for spacecraft-charging applications and have been found to underestimate charging effects by one to four orders of magnitude for …
Polarization Jet Events And Excitation Of Weak Sar Arcs, S. Sazykin, Bela G. Fejer, Y. I. Galperin, S. A. Grigoriev, L. V. Zinin, M. Mendillo
Polarization Jet Events And Excitation Of Weak Sar Arcs, S. Sazykin, Bela G. Fejer, Y. I. Galperin, S. A. Grigoriev, L. V. Zinin, M. Mendillo
Bela G. Fejer
[1] Polarization Jet (PJ), also known as Sub-Auroral Ion Drift (SAID), events are supersonic westward plasma drifts on the equatorward edge of the diffuse aurora in the evening and nighttime sector. Their optical F-region signatures are weak 630.0 nm red arcs colocated with regions of fast convection. These weak arcs resemble Stable Auroral Red (SAR) arcs observed during the recovery phase of magnetic storms, but have lower intensities, shorter lifetimes, and occur without a significant heat flux from the magnetosphere. Previous model studies underestimated the brightness of weak SAR arcs. We present calculations showing that ion-neutral collisional heating and ion …