Physics Commons^™

Medical Linear Accelerator Water Tank Measurements Optimization For Commissioning, Tyler R. Laugh

Theses and Dissertations

Beam commissioning is a critical component of linear accelerator (LINAC) implementation, requiring accurate measurement of percent depth dose (PDD), beam profiles, and output factors across a wide range of field sizes. Conventional commissioning workflows often require multiple detectors and can be time-intensive, particularly for small-field dosimetry where measurement accuracy is highly sensitive to detector characteristics. This study evaluated the performance of a plastic scintillation detector (BP-PSD) for full water tank commissioning and its potential to improve efficiency while maintaining dosimetric accuracy.

Beam data were acquired for field sizes ranging from 1 × 1 cm² to 40 × 40 cm² using …

A Mathematical Frameworks For Singular, Nonlinear Phenomena: Applications To Nematocyst Firing And Inhomogeneous Nls With Coulomb Potential, Abdulrahman Alharbi

Theses and Dissertations

Nematocysts are specialized cellular organelles found in all cnidarians, including corals and jellyfish, as well as in some single-celled protists such as dinoflagellates. These organelles display remarkable diversity in morphology and function, playing roles in prey capture and defense. The firing of a nematocyst is one of the fastest accelerations in nature, yet the underlying physical mechanisms remain not fully understood. In this work, we address key questions: how sufficient force is generated to overcome the fluid boundary layer, whether fluid–structure interaction models can reproduce observed dynamics, and what mechanisms trigger discharge.

Our research investigates models based on osmotic pressure …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

Developments And Applications Of Transport Of Intensity Equation Imaging And Optical Diffraction Tomography In Bioimaging, Shane D. Carney

Electronic Theses & Dissertations (2024 - present)

Non-invasive imaging schemes are highly sought after methodologies in biology and metrology, where maintaining the physical state of a sample is important. Quantitative phase imaging (QPI) techniques non-invasively reconstruct the relative phase delay imparted onto an optical field due to transmission through a sample. Phase delay is proportional to the thickness and refractive index of the sample, but is lost in the intensity measurement process. Digital holographic microscopy (DHM) and transport of intensity equation (TIE) phase imaging are two high-resolution QPI techniques. DHM is a well-researched, accurate, and widely implemented technique, but can be difficult to implement in labs without …

Retrieval And Characterization Of Aerosol Optical And Microphysical Properties Following Pyrocumulonimbus Events From Sageiii/Iss, Vishal G. Bagadia

Electronic Theses & Dissertations (2024 - present)

Stratospheric aerosols play an important role in maintaining global radiative balance with impacts to stratospheric equilibria through physical and chemical forcings.  Stratospheric aerosol size distributions, in particular aerosol size, are vitally important in determining the physical and chemical impacts of aerosols in the stratosphere. The representation of aerosol size and size distributions in most climate models contain large uncertainties due to relatively sparse sampling of stratospheric aerosols. Occultation measurements from satellite provide an unique opportunity to retrieve the aerosol size distribution using high quality aerosol extinction measurements. A retrieval algorithm is developed to characterize size distributions of stratospheric aerosols from …

Entropic Foundation Of Finance And Physics: Securities Price Dynamics And Quantum Theory, Mohammad Abedi

Electronic Theses & Dissertations (2024 - present)

In many scientific and financial contexts, we must reason and make predictions under conditions of incomplete information. This dissertation develops Entropic Dynamics (ED) as a unified framework for deriving dynamical laws directly from principles of inference. Within this approach, probability distributions represent states of knowledge, and their evolution is determined through entropy maximization subject to relevant constraints. This leads to a novel concept of entropic time and a formulation of dynamics as an inferential process. In this talk, I will present how ED provides a common foundation across multiple domains. In physics, quantum dynamics for particles and scalar fields in …

Tracking A Precessing Quantum Spin System: Extracting Data From Quantum Systems Using Bayesian Analysis, John Kaminski

Electronic Theses & Dissertations (2024 - present)

The parameters that govern the evolution of a quantum system can be determined by making measurements on an ensemble of identically-prepared systems. However, there are times when we are unable to recreate the experiment and want to measure physical parameters from just a single particle. For example, we may wish to measure the mass to charge ratio of a particle based on its track through a bubble chamber. Recent research [11, 12, 16] has suggested that classical behavior, defined as phenomenon that does not violate macroscopic realism, does not arise simply as a consequence of a quantum system of many …

Analytical Study Of Transient Mixed Convective Radiative Jeffrey Fluid Flow With Diffusion–Thermo And Chemical Reaction, V. Sathiya, R. Vijayaragavan, B. Rushi Kumar

Mansoura Engineering Journal

This research examines the behavior of unsteady mixed convective radiative Jeffrey fluid flow over a permeable moving plate with a diffusion thermo effect. The study incorporates multiple factors, including aligned magnetic fields, heat generation, radiation, and chemical reactions. The behavior of Jeffrey fluid under these combined conditions is particularly relevant to the design of efficient heat exchangers, MHD generators, and cooling systems for electronic components. A regular perturbation technique was employed to solve the governing equations, yielding distributions for velocity, temperature, and species concentration. These solutions enabled the derivation of expressions for skin friction, Nusselt number, and Sherwood number. Through …

Connecting The Existing Fiber Infrastructure To The Future With Antiresonant Hollow Core Fibers, Timothy Bate

Graduate Studies Theses and Dissertations 2026

Optical fiber systems based on solid-core silica waveguides underpin modern telecommunications, high-power laser delivery, precision sensing, and coherent optical systems. However, nonlinear effects, material absorption, and thermal limitations within silica increasingly constrain further scaling in both optical power and transmission performance. Antiresonant hollow-core fibers provide a promising alternative by guiding light predominantly in air, substantially reducing nonlinear interactions, latency, and optical damage while enabling transmission regimes inaccessible to conventional solid-core fibers. Despite rapid advances in antiresonant hollow-core fiber attenuation and power handling, one of the largest remaining barriers to widespread adoption is reliable integration with the existing solid-core fiber ecosystem. …

The Spacetime Finite Element Method For Investigations Into Physics Ghost Systems And Time Parallel Preconditioning, Jax Wysong

Electronic Theses and Dissertations

This work operates on two fronts, focusing on interesting physical phenomena before turning our attention to an interesting numerical math problem. First, using the spacetime finite element method (FEM), we investigate a PDE system consisting of two Klein Gordon equations, which are coupled nonlinearly through the potential energy. The system contains a ghost (negative kinetic energy term). Systems such as these are generally deemed physically unstable, resulting in infinite energy in finite time. However, recent work has shown that this is not always the case. We investigate multiple scenarios arising from different initial conditions to characterize if/when a ghost system …

Connecting Classroom Physics To Real-World Research: A Citizen Science Approach In Ap Physics 1, Heather M. Landgarten

West Chester University Graduate Theses, Dissertations, and Final Projects

Advanced Placement (AP) Physics 1 emphasizes evidence-based reasoning, quantitative modeling, and scientific inquiry. However, secondary science instruction often remains focused on procedural problem solving and standardized assessment rather than authentic scientific practice. This study examined the integration of citizen science projects into an AP Physics 1 curriculum to provide students with authentic research experiences while reinforcing physics concepts during the post-AP examination instructional period.

Using a classroom-based mixed-methods pre–post design, students participated in citizen science activities through publicly available research platforms, including Zooniverse. Students collected and classified authentic scientific data, analyzed real-world datasets, developed research questions, compared observations with theoretical …

Comparison Of Push-Pull Air Curtain To Overhead Downdraft Systems On Aerosol Containment And Distribution In Controlled Environments, Manal Mutairi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Comparison of Push-Pull Air Curtain to Overhead Downdraft Systems on Aerosol Containment and Distribution in Controlled Environments.

This dissertation looks at the ongoing issue of tiny airborne particles created during medical and dental procedures and evaluates ways to reduce the risk of exposure for healthcare workers and patients to these particles. The first study focuses on the size, how long particles stay in the air, and how far they travel from common medical procedures that create aerosols, showing that tiny particles (less than 5 µm) can stay in the air long enough to escape basic droplet controls. As a …

High-Resolution Laser Diagnostics For Ion Measurements In Magnetized Plasmas, Katey Stevenson

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this work, we investigate ion heating in two plasma systems (helicon plasmas and flux rope plasmas) using the PHAse Space MApping (PHASMA) experiment. Our studies rely on high-resolution laser diagnostics, specifically laser-induced fluorescence (LIF), to measure ion velocity distribution functions (IVDFs). The temperature and bulk flow of each species are inferred from their respective VDFs. This dissertation is organized into three main parts: the study of ion heating in helicon plasmas, pulsed LIF modeling and diagnostic development, and the study of ion heating in flux rope plasmas. Helicon plasma sources efficiently generate high-density plasmas and are widely used to …

Black Hole Spectroscopy And Tests Of General Relativity With Gw250114, Jaclyn (Jax) Sanders

Physics Faculty Research and Publications

The binary black hole signal GW250114, the loudest gravitational wave detected to date, offers a unique opportunity to test Einstein’s general relativity (GR) in the high-velocity, strong-gravity regime and probe whether the remnant conforms to the Kerr metric. Upon perturbation, black holes emit a spectrum of damped sinusoids with specific, complex frequencies. Our analysis of the postmerger signal shows that at least two quasinormal modes are required to explain the data, with the most damped remaining statistically significant for about one cycle. We probe the remnant’s Kerr nature by constraining the spectroscopic pattern of the dominant quadrupolar (ℓ=m=2) …

Analyzing Rydberg Atoms Of Rubidium At Room Temperature: Applying Electromagnetically Induced Transparency, Bridger Stiles

Honors Theses

This thesis describes an experimental exploration of electromagnetically induced transparency (EIT) in atoms of 85Rb using a new MOGLabs external cavity diode laser. A two-step ladder technique of EIT was applied using a 5S_1/2→5P_3/2 probe transition and 5P_3/2→nD_5/2 coupling transitions. Significant apparatus tuning was done, including developing a reliable procedure of regulating frequency and scanning the coupling laser over a sufficient mode-hop free range. A Doppler-reduced technique was applied by counter-propagating the probe and coupling beams through the Rb vapor cell. EIT signals were collected at various probe and coupling laser powers to analyze changes in signal size and linewidth. …

Three-Photon Rydberg Eit Lineshape Analysis In Rubidium, Jackson Lake

Honors Theses

Electromagnetically Induced Transparency detection of high-lying Rydberg states in room-temperature rubidium vapor was investigated using a four state ladder-type excitation scheme with light provided by three External Cavity Diode Lasers (ECDLs) at 780 nm, 776 nm, and 1266 nm. This detection technique was studied by characterizing the lineshape parameters of the EIT transmission peak, specifically the height, width and area of the transparency window as functions of the dressing and coupling laser powers. With the goal of characterizing the linewidth of the transmission signal, a confocal etalon was built and implemented in the optical setup to perform frequency calibration of …

Enhanced Hydrophilicity And Self-Cleaning Properties Of Tio₂ Thin Films On Glass For Photovoltaic Applications: Influence Of Precursor Concentration And Light Irradiation, Fatma Refaat, Hany Hashem, Mohamed Mahmoud Gouda, Ibrahim Ahmed, Khaled Abdelwahed, Ahmed Bakr El Basaty

Trends in advanced sciences and technology

This study investigates the modification of glass substrates with TiO₂ thin films to enhance surface hydrophilicity and self-cleaning behavior. The films were deposited on glass by spin coating using different precursor concentrations, followed by thermal treatment. Structural and optical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy, while surface wettability was evaluated through water contact angle measurements. XRD confirmed the formation of pure anatase TiO₂, while FTIR spectra verified the presence of Ti–O and Ti–O–Ti bonds. Wettability analysis showed that films prepared with the lowest precursor concentration exhibited the …

Gauge-Invariant Gravitational Wave Polarization In Metric F(R) Gravity With Cosmological Implications, Ramesh Radhakrishnan, David Mcnutt, Delaram Mirfendereski, Alejandro Pinero, Eric Davis, William Julius, Gerald Cleaver

Physics & Astronomy Faculty Publications

We develop a fully gauge-invariant analysis of gravitational-wave polarizations in metric 𝑓⁡(𝑅) gravity with a particular focus on the modified Starobinsky model 𝑓⁡(𝑅) =𝑅 +𝛼⁢𝑅2 −2⁢Λ, whose constant-curvature solution 𝑅𝑑 =4⁢Λ provides a natural de Sitter background for both early- and late-time cosmology. Linearizing the field equations around this background, we derive the Klein–Gordon equation for the curvature perturbation 𝛿⁢𝑅 and show that the scalar propagating mode acquires a mass 𝑚2𝜓 =1/(6⁢𝛼), highlighting how the same scalar degree of freedom governs inflationary dynamics at high curvature and the propagation of gravitational waves in the current accelerating Universe. Using the scalar–vector–tensor …

New Methods For Bright Electron Beam Generation At The Argonne Wakefield Accelerator Facility, Emily Frame

Graduate Research Theses & Dissertations

Bright electron beams generated via photoinjectors have enabled many recent developments in accelerator technology, including x-ray free electron lasers and ultrafast electron microscopy and diffraction systems. The conceptual design, scientific reach, and accessibility of these and next-generation accelerator applications can be significantly improved by increasing electron beam brightness. Therefore, the development of novel methods to further enhance beam brightness remains a critical priority in the field.

One of the primary factors limiting beam brightness is the mean transverse energy (MTE) of photoemitted electrons. The MTE is an intrinsic property of the photocathode and is proportional to the square of the …

4d-Qens And Diffuse Scattering: Analysis Of Dynamics And Local Ordering In Superionic Conductors, Jared Coles

Graduate Research Theses & Dissertations

Ionic conductors are increasingly central to electrochemical energy technologies because they enable charge transfer through the motion of mobile ions. Among them, superionic conductors are crystalline solids that exhibit exceptionally high ionic conductivities, making them promising candidates for safer and more sustainable next‑generation energy storage and conversion devices. Despite their technological importance, key gaps remain in our ability to connect macroscopic transport to microscopic structural disorder and correlated dynamics that enable fast‑ion motion. Neutron scattering provides a powerful set of tools for establishing these connections.

In total scattering experiments, Bragg diffraction measures the average crystallographic structure, while diffuse scattering probes …

Longitudinal Dechirping Of Electron Beams Using Negative Identity Drifts In A Transverse Deflecting Cavity-Based Chirper, Alex Desimone

Graduate Research Theses & Dissertations

Electron beam chirping for bunch compression is commonly achieved through off-crest acceleration in radio-frequency accelerating cavities. While it is effective, this method reduces average beam energy and introduces nonlinearities in the beam's longitudinal phase space, which can degrade beam quality in applications such as X-ray free electron lasers. An alternative chirping scheme has been proposed, in which accelerating cavities operate on-crest while transverse deflecting cavities generate the required longitudinal chirp. However, the efficiency of this approach and its impact on beam quality have not been systematically investigated, and the previously proposed dechirping scheme for this system is experimentally impractical. This …

Simulation And Experiment Of Two-Bunch Wakefield Dynamics And Energy Recovery In Dielectric-Lined Thz Structures, Calcifer Phillips

Graduate Research Theses & Dissertations

Beam-driven structure wakefield acceleration (SWFA) is a proposed method of particle acceleration that produces higher acceleration gradients. This technique could lead to the development of smaller and more efficient particle accelerators. In SWFA, a charged "drive" bunch passing through a dielectric or metallic structure created an electromagnetic "wake" field which can then be used to accelerate a following "witness" bunch. This work studies the effects of structure geometry on wake excitation, presents simulation results of wakefield dynamics in various geometries, and explores how SWFA could be used to achieve higher energy gradients. The use of a circular cross-section structure was …

High-Throughput Strip Clustering On Fpgas For The Hl-Lhc, Hayden Shaddix

Graduate Research Theses & Dissertations

With the advent of the High-Luminosity Large Hadron Collider (HL-LHC), the demand for modern approaches to high-throughput data processing has increased substantially. The HL-LHC will deliver far higher collision rates (pile-up reaching ⟨μ⟩ ∼200), producing a dramatic rise in detector activity and placing significant pressure on real-time reconstruction algorithms. One strategy for meeting this challenge is to leverage commodity hardware such as field-programmable gate arrays (FPGAs) and graphics processing units (GPUs), which can accelerate bandwidth-intensive portions of the reconstruction chain. In particular, FPGAs programmed through high-level synthesis (HLS) offer a promising balance between flexibility and performance, allowing physicists to design …

Beam Dynamics Of Non-Relativistic Proton Bunch Compression In Extreme Space Charge: Setting The Stage For Next Generation Intensity-Frontier Machines, Benjamin Simons

Graduate Research Theses & Dissertations

Next-generation intensity-frontier particle accelerators, such as the proposed Muon Collider and Neutrino Factories, require proton drivers capable of delivering high-intensity, short-pulse bunches. Achieving the required peak currents demands aggressive longitudinal compression, a process fundamentally limited by the extreme repulsive space-charge forces inherent to high-intensity, tightly compressed bunches.

Through the development and use of the FAST/IOTA Bunch Rotation Experiment (FI- BRE) at Fermilab as a dedicated testbed, this dissertation establishes a comprehensive physical design and simulation framework to probe these fundamental intensity limits. By isolating the dynamics of a 2.5 MeV non-relativistic proton beam (β ≈ 0.073) circulating in the Integrable …

Development And Characterization Of Flat And Flexible Rebco Cables For High-Field Accelerator Magnets, Emily Romancew

Graduate Research Theses & Dissertations

High-Temperature Superconducting (HTS) materials are at the forefront of innovation for fundamental particle physics. The next generation of particle accelerators aims to explore higher mass particles and is dependent on the ability to achieve higher fields in the 20–30 T range to keep machine size within a practical footprint. Current magnet technology relies on low-temperature superconductors (LTS) such as NbTi and Nb₃Sn, which are limited to fields of approximately 8–16 T, while high-temperature superconductors (HTS), particularly Rare-Earth Barium Copper Oxide (REBCO), offer a promising pathway toward higher-field magnets due to their ability to carry large currents at elevated magnetic fields. …

A Transmission Electron Microscopy Study Of Structural Design And Modifications Of Li And Na – Ion Battery Cathodes For Performance Optimization, Maksim Andreyevich Sultanov

Graduate Research Theses & Dissertations

The importance of Li ion batteries as an energy storage device cannot be understated. The industry around energy storage has been steadily growing over the last few decades and continues to grow. However, the design of these devices has run into a bottleneck as both academics and industry specialists try to achieve even higher performance parameters, as well as trying to supplement critical materials such as Co, Li and Ni while maintaining cost and energy density. In particular, energy density, capacity retention, thermal and mechanical stability have become very important to improve. These critical parameters within the device are dominated …

Dynamic Aperture Maximization Methods, Kevin J. Hamilton

Graduate Research Theses & Dissertations

Particle accelerators consist of some of the most prolific machines for achieving a long-standing history of successful experiments that have progressed fields such as particle physics, nuclear physics, solid state physics, and medical physics. In recent years, multiple studies have been conducted on how further progress in these fields can be made and the beams physics community has concluded that developing new accelerators to minimize the loss of particles, induce high intensity beams, and remain stable under perturbations is essential to the continued success of physics research. Each of these qualities correspond to finding methods to increase the so-called dynamic …

Rntuple For Atlas Analysis Workflow, Fatima Ariana Rodriguez

Graduate Research Theses & Dissertations

RNTuple is the new data storage format set to replace TTree at the start of the High-Luminosity LHC. An investigation was conducted to evaluate how analysis workflows for ATLAS researchers will change with RNTuple, using reading speed, writing speed, disk space, and memory consumption as metrics. In this study, all metrics were measured using converted RNTuple inputs from ATLAS Open Data, compared to their TTree equivalents. Additionally, RNTuples produced with the LZ4 compression algorithm were generated and compared with those produced using ZSTD. Finally, two new versions of the Analysis Grand Challenge (AGC) using ATLAS Open Data were completed for …

Entropic Dynamics Approach To The Classical Limit Of Quantum Mechanics: Decoupling Of The Center Of Mass Motion For A Mesoscopic Particle, Fatimah Judayba

Electronic Theses & Dissertations (2024 - present)

In the Entropic Dynamics (ED) approach, quantum mechanics is derived from the principles of entropic inference and information geometry. The ED approach differs from other interpretations by making a clear commitment to distinguishing which variables are ontic (real) and which are epistemic. The classical limit for the center of mass (CM) coordinate is achieved for a large number of particles, M →∞, while Planck’s constant ℏ remains finite. Typically, the emergence of the classical limit requires decoherence through interactions with the external environment. In this work, we investigate whether the classical behavior of the CM coordinate in a mesoscopic system …

On Quantum Processes And The Epistemic Constraints, Varun Immanuel Premkumar Immanuel

Electronic Theses & Dissertations (2024 - present)

This doctoral dissertation on the foundations of quantum theory tells the story of a conceptual protagonist I have called “Epistemic Constraint.” Here, epistemic constraints are the definite, intersubjectively agreeable, ordinary-language conditions under which experiments are described.

The usual formulation of the quantum measurement problem, which I call the Schrodingerian measurement problem, has the structure of an anomaly: if we take quantum theory at face value, we expect no definite values, and yet we see definite values in experiments. The responses to this problem have been either to solve it or to dissolve it. These responses, which have taken the form …