Physics Commons^™

Harnessing Coherent-Wave Control For Sensing Applications In Scattering Media, Pablo Xavier Jara Palacios

Doctoral Dissertations

"Diffuse electromagnetic waves are widely used for non-invasive sensing and imaging in complex scattering media such as biological tissues. A fundamental limitation of such techniques is the scarcity of detected photons: as the source-detector separation increases to access deeper regions of the medium, the signal strength decays rapidly, leading to poor signal-to-noise ratio and limited sensitivity. This dissertation addresses this challenge through a combination of theory and computation.

We show that coherent control of the incident optical wavefront can compensate for the scarcity of detected photons that limits conventional diffuse optical imaging, typically performed in the near-infrared spectral region. By …

Spectral Phase Pulse Shaping Alters Photoionization Time, James Aygun, Dany Yaacoub, Allison L. Harris

Faculty publications – Physics

Photoionization is a key step in many attosecond processes. Accurately determining the photoionization time delay is critical to understanding electron dynamics during and after ionization and can guide future efforts to manipulate electron motion. Prior studies have shown that the photoionization time delay is non-zero and that pulse shaping through alteration of the spectral phase may change the number and timing of ionization events. In order to assess whether and how the spectral phase modifies the photoionization time delay, we use attosecond streaking simulations to extract the streaking time delay for ionizing pulses with identical power spectra, but different spectral …

Optimizing Microscale Tesla Valve Design For Enhanced Efficiency For Filtering And Sorting Bacteria, Brian Ewalt

2026 Research Poster Competition

Invented by Nikola Tesla in 1920, a Tesla valve is a passive check valve with no moving parts but showing diodicity for fluids (i.e., allowing fluids to flow easily in one direction but not in the other). Tesla valves have demonstrated remarkable versatility across a range of scientific fields. Recently, a study conducted at the University of Arkansas showed that these conduits exhibited diodicity for bacteria in the absence of fluid flows (Rogers et al. 2023), serving as proof of concept for applying microscale Tesla valves for filtering and sorting bacteria and microorganisms in biomedical settings. However, the design of …

Detection And Quantification Of Spreading Depolarization In Drosophila Melanogaster Using High-Throughput, Wide-Field Brain Imaging, Wolfgang Stein, Allison L. Harris

Faculty publications – Physics

Spreading depolarization (SD) is a ubiquitous neural phenomenon implicated in mammalian neurological disorders including cerebral ischemia, brain death, stroke, brain injury, and migraine, as well as in insect chill coma. During SD, a breakdown of ion homeostasis and a slowly spreading wave of neural depolarization leads to processing deficits, such as sensory disturbances and paralysis. Our protocols introduce high-throughput techniques using wide-field fluorescence brain imaging in Drosophila melanogaster larvae and adults to detect and quantify the spatial and temporal dynamics of SD and its initiation points. Two SD initiation techniques, rapid cooling and pharmacological manipulation, are detailed. The larval protocols …

A Nuclear Terrorism Scenario: Improvised Nuclear Weapons With 60%-Enriched Uranium, Matt Caplan

Faculty publications – Physics

In this work we show that approximately 60–70 kg of 60%-enriched uranium can be used to build a crude nuclear weapon with a kiloton yield. While too large to fit on a missile, such a weapon could be delivered by a shipping container. This analysis is motivated by the June 2025 Israeli and US attacks on Iran, especially the bombings of the nuclear facilities at Natanz, Fordow and Isfahan. The Iranian stockpile of approximately 440 kg of 60%-enriched uranium is, at the time of writing, inaccessible to IAEA inspectors and stored in secret. The rapid clandestine relocation of this material …

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 …

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 …

Elastohydrodynamic Propulsion Of A Magnetically Actuated Filament, Sohum Kapadia, Julien Chopin, Arshad Kudrolli

Physics

We investigate the low-Reynolds-number propulsion of a slender elastic filament with a dipolar magnetic head actuated by an oscillating magnetic field in a viscous fluid by studying its strokes and net forward motion. To capture these dynamics, we employ an elastohydrodynamic (EH) framework that couples Euler-Bernoulli beam mechanics with resistive force theory. Unlike prescribed-kinematics models, filament shapes here emerge self-consistently from the actuation and the force and torque boundary conditions (BCs). We demonstrate that viscous boundary contributions are crucial for quantitative agreement and show that the swimming dynamics are governed by the EH length and a magneto-viscous-elastic stroke amplitude introduced …

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 …

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 …

Quantum Mechanics As A Framework For Data Assimilation And Its Application To Atmospheric Parameterization, David Freeman

Dartmouth College Ph.D Dissertations

Quantum mechanics, as a mathematical system, can be understood as a generalization of classical probability theory. Quantum Mechanical Data Assimilation (QMDA) is a method in which classical dynamical systems are embedded into a quantum mechanical setting, with an associated data assimilation scheme leveraging the operator algebraic setting. In this dissertation, the algebraic structure underlying the operator theoretic formulation of QMDA is discussed. A procedure for closure of dynamical systems based on QMDA, known as Quantum Mechanical Closure (QMCl), is then constructed, and the procedures for constructing the quantum embeddings and implementing QMCl in practice are laid out and implemented for …

Improving The Quality Of Physics Practice, Wyatt W. Thompson

All Graduate Theses, Dissertations, and Other Capstone Projects

This case study started with personal observations and experiences. As a lab teaching assistant, I observed on many occasions that students do not like their current homework platforms, often venting to me about their frustrations during lab time. As a student, I shared similar sentiments with them. To develop a possible solution to these observations, a theory of reasoning was chosen as the foundation. The heuristic-analytic theory of reasoning (HATR) suggests that people present an epistemic model (beliefs and ideas about a phenomenon) through a heuristic process (generation from memory) and engage in an analytic process to validate the epistemic …

Memory Effects In Many-Body Systems, Jeffrey Beckstrand

Master's Projects

This thesis investigates memory effects in many-body systems through the MoriZwanzig Formalism for projected dynamics of a Hamiltonian System which yields the Generalized Langevin Equation (GLE). The GLE is a stochastic differential equation (SDE) that studies the dynamics of observables under the effects of many other observables in the system. Although satisfying, the GLE has a term called the Memory Kernel that encodes the past of the system and introduces a computational challenge by introducing a non-Markovian property to the equation. The kernel is often approximated by introducing a delta function, which simplifies the computation, but at the loss of …

Gpu And Pso Accelerated Low-Latency Fully-Coherent All-Sky Search For Compact Binary Coalescences, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

The fully-coherent all-sky (FCAS) search, which combines data from a gravitational wave detector network into a single likelihood function, is the preferred method prescribed by statistical theory for Gaussian noise. However, so far, its exorbitant computational cost has blocked its use for compact binary coalescence searches. We introduce a solution combining Particle Swarm Optimization with Graphics Processing Unit (GPU) acceleration that is ≈ 50-fold faster than real-time analysis. This transforms the prospect of a low-latency FCAS search on all GW data into a practical reality for the first time. With large-scale simulations enabled by this speedup, we examine the issue …

Efficient Search For Detection Candidates Using A Peak Finder Strategy For All-Sky-All-Frequency Gravitational Wave Radiometer, Arindam Sharma, Deepali Agarwal, Sanjit Mitra

Physics & Astronomy Faculty Publications

The first all-sky-all-frequency (ASAF) radiometer search was conducted using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. The significance of this search lies in its fast and unmodeled approach, leveraging a cross-correlation technique to identify common signals across the detector network. As a result, this method serves as an excellent alternative to search for unknown or poorly modeled continuous wave sources and narrow band components of the gravitational wave (GW) background. For continuous wave sources whose waveform can be modeled, this method can serve as the first stage of a hierarchical scheme by …

Scalable Continuous Gravitational Wave Detection In Pta Data With Nonparametric Red Noise Suppression And Optimal Pulsar Selection, Yi-Qian Qian, Yan Wang, Soumya Mohanty, Siyuan Chen

Physics & Astronomy Faculty Publications

Bayesian methods for the detection of continuous gravitational waves (CGWs) in pulsar timing array (PTA) data incur substantial computational costs that grow rapidly due to the number of noise and signal parameters characterizing the fitted model being proportional to the size of the PTA. This computational burden limits the scalability of these methods for large-scale PTAs comprising hundreds of pulsars anticipated from next-generation radio astronomy facilities. In this work, we introduce a computationally efficient frequentist method designed to circumvent this challenge. This is achieved by combining an adaptive spline fitting algorithm that nonparametrically suppresses red noise, thereby eliminating the need …

Advanced Optical Coupling And Testing Techniques For Silicon, Silicon Nitride, Silicon Germanium And Lithium Niobate Nanophotonic Devices, Adarsh Ananthachar

Theses

Testing in the field of photonics, particularly for photonic devices, is a critical step that ensures the reliability and performance of these sophisticated components. Photonic integrated circuits (PICs), which are at the heart of many modern optical systems, require rigorous testing to validate their functionality and efficiency. This thesis investigates sophisticated testing methods for various nanophotonic devices on platforms like Silicon, Silicon Nitride, Silicon Germanium and Lithium Niobate. It starts by introducing the fundamental tools and processes involved in fabricating these devices. The study then provides a detailed theoretical understanding of different devices, including Photonic Crystal (PhC) cavities, grating couplers …

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) …

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 …

Informationally-Optimal Measurements On Single-Qubit Systems, Adam V. Preston

Electronic Theses & Dissertations (2024 - present)

This thesis will focus on deriving informationally-optimal quantum state tomographic measurements on single-qubit systems, with the definition of informationally optimal to be defined as those measurements which maximize the average information gain. The informationally-optimal measurements that will be covered include projective measurements (formally building off of the work of [1] and putting it on firm, information-theoretic foundations), and more general types of quantum measurements called directional (also known as rank-one) positive operator-valued measure (POVM) measurements, and, finally, adaptive directional POVM measurements.

For projective measurements, we build on the work of Wootters and Fields ([1]) and show, via analytical methods and …

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk, Yasir A. Alshehry, Matthew S. Halquist Phd, Sandro R.P. Da Rocha Phd

Graduate Research Posters

Background

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance …