Physics Commons^™

Serendipity Shape Function For Hybrid Fluid/Kinetic-Pic Simulations, Trevor V. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Sun in our solar system and stars are capable of generating enormous amounts of energy. The process by which these gaseous, celestial bodies are able to produce such large amounts of energy is called thermonuclear fusion. Fusion happens when particles collide with one another at energy levels high enough to overcome the Coulomb force and then release vast amounts of energy. Plasma, the fourth state of matter, is the natural state of stars. Plasma is an ionized gas that consists of negatively and positively charged particles. Stars, which have immense mass, can confine the plasma through their gravity to …

Relativistic, Continuum Drift-Kinetic Capability In The Nimrod Plasma Fluid Code, Tyler Markham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A ”runaway” electron is an electron that, through a self-reinforcing process, accelerates to relativistic speeds. At multiple points during tokamak discharges, relativistic runaway electron (RE) beams can form. RE beams pose a serious risk in the form of severe damage to plasma facing components in ITER and future burning plasma reactors. Early RE studies used simplified geometric and transport models, but enabled feedback on the overall plasma evolution. This feedback is important for understanding the evolution of the RE current column. The work in this thesis is an important step toward self-consistently evolving an RE distribution in the plasma fluid …

Graviweak Theory In Bicomformal Space, Mubarak Ukashat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are four basic forces in nature: the electromagnetic force, which accounts for interactions of particles with charges; the weak force, which is responsible for radioactive decay; the strong force, which holds the particles inside a nucleus tightly bound together; and the gravitational force, which is responsible for keeping us on our beautiful planet, Earth and holding together our entire solar system. Physicists have been on the hunt for a theory that can single-handedly explain all these forces under the same underlying mathematical formulation. So far, physicists have suceeded in unifying the electromagnetic and weak forces in what is called …

Inertial Motion On The Earth's Spheroidal Surface, Boyd F. Edwards, Cade Pankey, John M. Edwards

All Physics Faculty Publications

As seen by an observer in the rotating frame, the earth’s small spheroidal deformations neutralize the centrifugal force, leaving only the smaller Coriolis force to govern the “inertial” motion of objects that move on its surface, assumed smooth and frictionless. Previous studies of inertial motion employ weakly spheroidal equations of motion that ignore the influence of the centrifugal force and yet treat the earth as a sphere. The latitude dependence of these equations renders them strongly nonlinear. We derive and justify these equations and use them to identify, classify, name, describe, and illustrate all possible classes of inertial motion, including …

Round Robin Tests Of Electron Irradiated Polymers Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison, Virginie Griseri

Physics Student Research

Charge accumulation and migration can be studied using the pulsed electroacoustic (PEA) method to directly measure internal charge distributions in dielectric materials. This study aims to compare measurements using PEA systems constructed in labs at Utah State University and Université Paul Sabatier to establish confidence in comparing PEA results between different PEA systems. While there is good agreement in data measured for pristine samples with DC bias applied and no charge embedded, there are discrepancies in the data when measuring irradiated samples with embedded charge. The overall characteristics of charge distributions measured with both systems is clearly the same, but …

Pulsed Electroacoustic Measurements Of Polymers Irradiated With Low Energy Monoenergetic Electrons, Zachary Gibson, Jr Dennison

Physics Student Research

Understanding the dynamics and accumulation of embedded charge in dielectric materials is paramount for many applications from HVDC power transmission to spacecraft charging. The pulsed electroacoustic (PEA) method allows for nondestructive measurements of embedded charge distributions in dielectrics. The spatial resolution of PEA measurements are typically ~10 μm. However, some of the most deleterious spacecraft charging events result from electron fluxes with 10 keV to 50 keV energies, resulting in electron ranges of 1's to 10's of μm. Due to the resolution of the PEA method and the superposition of the interfacial charge with the deposited charge distribution, it is …

Quantum Computing Simulation Of The Hydrogen Molecule System With Rigorous Quantum Circuit Derivations, Yili Zhang

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Quantum computing has been an emerging technology in the past few decades. It utilizes the power of programmable quantum devices to perform computation, which can solve complex problems in a feasible time that is impossible with classical computers. Simulating quantum chemical systems using quantum computers is one of the most active research fields in quantum computing. However, due to the novelty of the technology and concept, most materials in the literature are not accessible for newbies in the field and sometimes can cause ambiguity for practitioners due to missing details.

This report provides a rigorous derivation of simulating quantum chemistry …

Toward A Conceptual Approach To The Coriolis Force: Cataloging Intuitive Knowledge Elements In Intermediate Physics Learners, Jared B. Arnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Physics, the topic of the Coriolis force is often confusing and difficult to teach. I conducted a series of interviews with undergraduate physics students to understand how they would use their prior knowledge and personal experiences to interact with and navigate through a new conceptual teaching approach for the Coriolis force. Many students applied their intuitive understanding of balance to interpret and make predictions about the Coriolis force. Some students displayed a strong conviction that rotating objects will naturally get pulled outward, which suggests that this impression may be a useful tool for novice physics learners to use in …

Uncertainties Of The Pulsed Electroacoustic Method: Peak Positions Of Embedded Charge Distributions, Zachary Gibson, J. R. Dennison

Physics Student Research

The pulsed electroacoustic (PEA) method allows for nondestructive measurements of internal charge distributions in dielectric materials. These measurements have been paramount in understanding and mitigating charge accumulation, aging, and electrostatic discharge in materials for various applications. This study aims to examine more closely the uncertainties of pulsed electroacoustic measurements. The first few moments of a charge distribution are directly related to the magnitude, peak position, full-width-at-half-maximum, and skewness. The uncertainty in the magnitude of the charge distribution is often quite large, but the peak position can be determined with a precision of <1 μm. This has been demonstrated in our lab with repeated PEA measurements of polyether-etherketone (PEEK) with internal charge present. This precision is further validated with measurements of PEEK irradiated with differing doses of 50 keV incident electrons, resulting in peak positions that differ by only a few μm. A final test is given by measurements monitoring the slow migration of the charge distributions in these irradiated samples over several months. The measured shifts in the peak position of the charge distributions are ≤1 μm. Though the spatial resolutions of PEA measurements are typically ~10 μm, as defined by the full- width-at-half-maximum of the leading interfacial peak, the precision of the peak position can be more than an order of magnitude greater. The statistical analysis of the repeated measurements to determine uncertainties, as well as the validation measurements, demonstrate the high precision determination of the peak position of embedded charge distributions.

What Is A Photon? Foundations Of Quantum Field Theory, Charles G. Torre

All Physics Faculty Publications

This is a brief, informal, and relatively low-level course on the foundations of quantum field theory. The prerequisites are undergraduate courses in quantum mechanics and electromagnetism.

Introduction To Classical Field Theory, Charles G. Torre

All Complete Monographs

This is an introduction to classical field theory. Topics treated include: Klein-Gordon field, electromagnetic field, scalar electrodynamics, Dirac field, Yang-Mills field, gravitational field, Noether theorems relating symmetries and conservation laws, spontaneous symmetry breaking, Lagrangian and Hamiltonian formalisms.

Normal-Mode Oscillations For The Circular And Dipolar States Of A Filled Hexagonal Magnetic Dipole Cluster, Peter T. Haugen, Andrew D. P. Smith, Boyd F. Edwards

All Physics Faculty Publications

We analyze the rotational dynamics of six magnetic dipoles of identical strength at the vertices of a regular hexagon with a variable-strength dipole in the center. The seven dipoles spin freely about fixed axes that are perpendicular to the plane of the hexagon, with their dipole moments directed parallel to the plane. Equilibrium dipole orientations are calculated as a function of the relative strength of the central dipole. Small-amplitude perturbations about these equilibrium states are calculated in the absence of friction and are compared with analytical results in the limit of zero and infinite central dipole strength. Normal modes and …

Large Earthquakes' Effect On The Ionosphere, Aaron Houston

Physics Capstone Projects

The ionosphere is a part of the Earth’s atmosphere that stretches from 80 – 600 kilometers. Gases in this area are ionized which creates a range of free electrons that make up the plasma of the ionosphere. A group of these electrons is known as Total Electron Content (TEC), which is responsible for signal delays between satellites in orbit and their GPS receivers on the surface. Using this delay, the TEC in a specific region can be calculated. This helps in GPS error analysis. During the earthquake in Japan on March 11, 2011, there was allegedly a noticeable jump in …

Improving The Efficiency Of The Preconditioning Of Iterative Solutions To The Kinetic Equation, D. Caleb Price

Physics Capstone Projects

To achieve the reality of fusion, a greater understanding of plasma is required. The kinetic equation can be evolved simultaneously alongside the fluid equations to solve for kinetic closures. NIMROD performs this with numerical solvers where the General Minimum Residual (GMRES) solver becomes more efficient with a preconditioning matrix as input. Using a GPU-enabled library, the efficiency of GPU offloading to the preconditioning step was tested. A significant decrease in the factoring time of preconditioning matrix was observed. This suggests that the allocation of GPUs is worth investigating for NIMROD’s own benefit, but also anyone seeking to improve the efficiency …

Seasonal Variations In Global Ionospheric Total Electron Content, Jason Knudsen

Physics Capstone Projects

As the Sun ionizes atoms and molecules in the Earth’s ionosphere, the region of atmosphere above approximately 100 km in altitude, the created ionization in this region affects many of the systems that we rely on in daily life. This includes cellular service, GPS navigation, weather forecasting, and credit card data. A good measure for the level of ionization in the ionosphere is total electron content (TEC), which is the number of electrons in a square column above a given geographic location. The TEC over a geographic location influences the propagation of radio waves that traverse that section of the …

Acoustic Waves In The Upper Atmosphere, Geoffrey Blayne Schulthess

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Atmospheric waves can be generated by tropospheric sources such as earthquakes and explosions, causing significant disturbances in the upper atmosphere and ionosphere, where radio wave communications take place. For this analysis, they will be separated into two sub-groups called acoustic waves and gravity waves. Because each of these waves have unique frequency ranges, they can be observed and measured in order to determine their source type and location. Past studies attempted to build the connections between these waves with severe storms and earthquakes, which have improved our understanding of their complexity. Because of the complex nature of these waves, simplified …

Yang-Mills Sources In Biconformal Double Field Theory, Davis W. Muhwezi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There is a robust and unifying approach to unraveling the roiling mysteries of the universe. Our most compelling accounts of physical reality at present rest on symmetry arguments that are conspicuously geometrical!

105 years ago, Albert Einstein derived gravity from Riemannian geometry. In the general theory of relativity, the world of our experience is a pseudo-Riemannian manifold whose curvature represents the gravitational field. Encoded in the Einstein field equation is how matter sources (energy-momentum tensor) couple to gravity (spacetime curvature). Schematically, the Einstein equation exhibits a more general structure:

Curvature of Spacetime = Material Sources

On one side of the …

Characteristics Of Mesospheric Temperature And Gravity Waves Over Chile In 2020-2021, Damien M. Devitt, Kenneth Zia

Physics Capstone Projects

Gravity waves (GWs) are often confused with gravitational waves in the fabric of space time. However, there is a clear distinction between them. Gravity wave is a term used by the atmospheric research field to describe perturbations in the atmosphere. Gravity pulls the perturbations down and causes oscillations, these present in the form of waves. The best visualization is to think of ripples on a pond, as the ripple reaches its peak gravity pulls the ripple down and creates an oscillating effect.

Modeling The Effects Of Surface Roughness On Electron Yield, Trace Taylor, Matthew Robertson, Jr Dennison

Conference Proceedings

Surface conditions—including surface morphology, composition, contamination, and oxidation—can significantly affect electron yields and consequently spacecraft charging. The effects of surface roughness on electron yield are modeled in this study by considering four aspects of electron yield calculations: (i) simple models of rough surface geometry, (ii) the angular distributions of electrons emitted from various points on these surfaces, (iii) the likelihood of these emitted electrons escaping the rough surface, and (iv) the relative fractions of smooth and rough surfaces. Three simple periodic one-dimensional surface profiles were considered—namely rectangular, triangular, and sawtooth features; each surface profile was characterized by an aspect ratio …

Laboratory Simulations Of Simultaneous Reduced Gravity And Ionizing Radiation Environments, Achal Duhoon, Jr Dennison

Conference Proceedings

A novel system has been developed to simulate the combined effects of reduced gravity and ionizing radiation present during spaceflight on biological and particulate samples. The miniature rotary cell culture system (mRCCS) was designed to synchronously rotate up to five independent vessels containing particulate samples suspended in fluid media, constructed using radiation tolerant, biocompatible, and vacuum compatible materials. Reduced gravity conditions were achieved when particles (e.g., 200 µm polystyrene microcarrier beads with or without adhered cell clusters) were suspended inside the vessels moving near terminal velocity in viscous fluid media with densities matched to the suspended …

The Relevance Of Pulsed Electroacoustic Measurements For Spacecraft Charging, Zachary Gibson, J. R. Dennison

Physics Student Research

The magnitude and spatial distribution of charge embedded in dielectric materials and the evolution of the charge distributions with time are at the heart of understanding spacecraft charging. Spacecraft materials are charged primarily by incident fluxes of low energy electrons, with electron fluxes in the 10 keV to 50 keV range often responsible for the largest deleterious arcing effects. While the pulsed electroacoustic (PEA) method can provide sensitive non-destructive measurements of the internal charge distribution in insulating materials, it has often been limited for spacecraft charging applications by typical spatial resolutions of ≤10 μm, with a 10 μm range of …

Utah's Food Processing Industry Can Manufacture Products From Cbd-Containing Lipids That Have Superior Texture And Consistency, Joseph Cooney, Isaac Hilton

Research on Capitol Hill

Sophomore Joseph is an Honors student and Undergraduate Research Fellow studying physics. Freshman Isaac, of Kaysville, studies civil and environmental engineering. Joseph and Isaac are exploring how cannabinoids impact the way that lipids function. A common way CBD is packaged is within foods, where it is frequently added to fats like cocoa butter or palm oil, and as the market for such products increase producers need to understand CBD will change the behavior of the fats they are using.In addition to this work, Joseph also volunteers for a physics lab. “Undergraduate research has let me explore fields outside my major …

The Surface Conditions Of Spacecraft Panels May Significantly Affect Spacecraft Survivability, Trace Taylor

Research on Capitol Hill

USU junior Trace grew up in Brigham City and studies physics and electrical engineering. The majority of spacecraft failure is caused by electron charging on the outer surfaces of the craft. Additionally, contaminants on the craft can cause a film over surface panels, increasing the problem. Trace is studying how roughness on panels can mitigate this contamination as it affects the charging that can lead to craft failure. This research will help determine what optimal panel materials should be used in future spacecraft construction. Trace started research almost as soon as he came to campus in his freshman year, and …

Hysteretic Transition Between States Of A Filled Hexagonal Magnetic Dipole Cluster, Andrew D. P. Smith, Peter T. Haugen, Boyd F. Edwards

All Physics Faculty Publications

By minimizing the magnetostatic potential energy and by finding zeros in the sum of the squares of the torques, we find the equilibrium states of six dipoles of identical strength at the vertices of a regular hexagon and a variable-strength dipole at the center. The seven dipoles spin freely about fixed axes that are perpendicular to the plane of the hexagon, with their dipole moments directed parallel to the plane. When the central dipole is weak compared with the perimeter dipoles, a ‘‘circular’’ state applies in which the perimeter dipole moments circle around the central dipole, which points toward a …

Scattering Of Light From Periodic Conducting Nanostructures, Wesley Mills

Fall Student Research Symposium 2021

Light scattered from periodic structures generates numerous fascinating phenomena, from diffraction patterns to the black patches on some butterfly wings. The simple scalar wave formulation based on Huygens principle can account for many diffraction and radiation patterns in the far field. However, when the structure dimensions are smaller than the wavelength, light polarization and structure details become important, and the vector formulation based on Maxwell's equations is necessary. I will present an analytic calculation and a numerical simulation on light scattering from two-dimensional conducting grids to model the reflectance from butterfly wings and broadband absorption structures made from carbon nanotube …

Equivalence: A Covariantly Constant Problem In General Relativity, Jaren Hobbs

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

In studying the space-time structures described by Einstein’s theory of general relativity, it is often useful to identify particular properties referred to as geometrical invariants. These are attributes of the space-times which do not change regardless of the underlying coordinate systems used to study them. This project is part of a larger effort to catalogue space-times studied in general relativity. Specifically, computational software was used to identify structures known as covariantly constant vector fields.

Absolute Neutral Densities And Temperatures And Their Climatologies In The Middle Atmosphere Using An Optimal Estimation Method With Rayleigh-Scatter Lidar Observations Obtained At Utah State University, Jonathan L. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Earth’s atmosphere is comprised of layers which can be defined by their temperature characteristics. These layers are the troposphere, stratosphere, mesosphere and thermosphere. The region where life exists is in the troposphere, however the study of the layers above is important as changes in these regions can directly impact, or indicate significant changes in, weather in the troposphere. The mesosphere is the least well-known region because it is the most difficult to observe. One of the best tools for observing this region is the Rayleigh-scatter lidar. It is capable of remotely observing the entirety of the mesosphere with good …

The Internal Charge Evolution Of Multilayered Materials Undergoing Mono-Energetic Electron Bombardment, Gregory Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The charging of multilayer materials as related to the charging of spacecraft is one of the primary concerns related to activities in the space environment. To understand how multilayer materials undergoing electron bombardment charge, an in-depth study of energy-dependent material properties must be undertaken. These properties include the electron penetration depth, secondary electron emission, charge transport and electrostatic discharge. By using energy dependent models of these properties, along with the geometry of the system, multilayer models can be developed to predict the time evolution of the internal charge distribution. Using these models, the net surface potential and the measurement of …

Geometrization Of Perfect Fluids, Scalar Fields, And (2+1)-Dimensional Electromagnetic Fields, Dionisios Sotirios Krongos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Rainich equations provide a purely geometrical interpretation of matter in terms of the gravitational field it generates. All this takes place within the geometrical formulation of gravity provided by Einstein’s General Theory of Relativity. Rainich-type conditions giving spacetime "goemetrizations" are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and electromagnetic fields.

Charge Transport In Dielectric: The Pulsed Electroacoustic Method, Zachary Gibson

Physics Student Research

Understanding and predicting charge accumulation and transport in dielectric materials is vital in applications where excess charge can accumulate including semiconductor devices, high-power electronic devices, high voltage DC cabling, high-energy physics facilities, plasma chambers, and spacecraft charging. Excess charge accumulation may result in electrostatic discharge events, which are the leading cause of spacecraft failure due to the space environment. The pulsed electroacoustic method allows you to “pop the hood” and non-destructively directly measure the embedded charge distributions in dielectric materials. Charge transport in disordered dielectric materials, measurements with the pulsed electroacoustic system, and comparison to models will be presented.