Physics Commons^™

Early Warning Detection Of Gravitational Waves With Sgnl, Megan Norris

Honors Theses

Gravitational waves (GWs) provide a whole new spectrum with which to observe astrophysical events. Multi-messenger observations including GWs are of particular interest, and these are best facilitated by early warning searches of GWs, which are typically aimed at detecting binary neutron star (BNS) mergers. This work provides an introductory overview of gravitational waves and summarizes the origins and basic physical properties of neutron stars and black holes in binary systems, focusing on BNS mergers and the detection of gravitational waves with LIGO using a modeled search. We assess the performance of a new GW search pipeline called SGNL to evaluate …

Measurements And First Principles Calculations On The Non-Centrosymmetric Superconductor Aupb3, Meena Shrestha

Dissertations

AuPb₃ is a non-centrosymmetric superconductor that crystallizes in a tetragonal structure and undergoes a superconducting transition at 4.4 K. Non-centrosymmetric superconductors that lack inversion symmetry are predicted to have an admixture of spinsinglet and spin-triplet symmetry induced by strong antisymmetric spin-orbit coupling (ASOC).

In this work, we investigated the normal and superconducting properties of AuPb₃. We also carried out the Density Functional Theory (DFT) calculations to study the strength of ASOC and its impact on vibrational and electronic properties. A high-quality polycrystalline sample of AuPb₃ was grown and characterized by powder x-ray diffraction, scanning electron microscopy, …

Probing Shielding Tensor Components Of Amino Acids Using Nuclear Magnetic Resonance, Shiva Agarwal

Dissertations

Chirality is fundamental to terrestrial life. While most amino acids exist as nonsuperimposable mirror images, amino acids in terrestrial life are homochiral, with the L-enantiomer being ubiquitous. The detection of an excess of L-amino acids in carbonaceous meteorites suggests that extraterrestrial processes may have contributed to this enantiomeric excess (ee). One proposed mechanism, the magnetochiral model, provides a potential explanation for this phenomenon in stellar environments characterized by strong magnetic and electric fields and the presence of relativistic leptons. According to this model, subtle differences in the electronic environments of chiral amino acids under such conditions …

Single-Shot Mev-Resolution Hard X-Ray Spectrograph For Cavity-Based X-Ray Free Electron Laser, Keshab Kauchha

Dissertations

The Cavity-Based X-ray Free Electron Laser (CBXFEL) is a possible future direction in the development of fully coherent hard X-ray sources of high spectral brilliance, a narrow spectral bandwidth of ≃ 1 − 100 meV, and a high repetition rate of ≃ 1 MHz. A diagnostic tool is required to measure CBXFEL spectra with a meV resolution on a shot-to-shot basis.

The CBXFEL hard X-ray spectrograph is designed to image 9.831 keV X-rays in a ≃ 200 meV spectral window and with a spectral resolution of a few meV using an LCLS XFEL (Linac Coherent Light Source X-ray Free Electron …

Computational Modeling In A Calculus-Based Physics Lab: Students’ Problems And Successes In Physics 2060, Abigail Sophia Flowers

Masters Theses

In the past few decades, computational modeling skills have become essential for students who want to pursue careers in physics or engineering. This issue of how to incorporate these skills into students' learning has become an important one because students in these degrees are already required to take several cognates outside of their chosen major. In 2018, Western Michigan University’s physics department decided to take on this issue by reformatting their introductory calculus-based physics labs to include computational modeling within the labs. The labs were first run in the Fall of 2018 and then were improved in spring 2019. When …

Einstein Field Equations And The Solutions For Uncharged Black Holes, Yogesh Mahat

Masters Theses

The General Theory of Relativity, formulated by the brilliant mind of Albert Einstein, stands as one of the most fundamental and revolutionary pillars of modern physics. This elegant theory of gravity not only offers a comprehensive explanation of the workings of the universe on a large scale, but it has also paved the way for groundbreaking advancements in the field of mathematics. This thesis begins by providing a concise overview of the key mathematical principles that are crucial to understanding Einstein’s theory. These principles form the basis for deriving the field equations that Einstein introduced. From there, these equations are …

Probing Shielding Tensor Components Of Amino Acids Using Nuclear Magnetic Resonance, Shiva Agarwal, Sungsool Wi, Michael Famiano, John Miller, Zbigniew Chajecki

Waldo Library Student Exhibits

Amino acids combine to form proteins in living organisms; most are chiral. On Earth amino acids appear only in the L- form, which is likely due to the amplification of enantiomeric excess (ee). However, a small ee for the L-form of amino acids has been observed in meteorites that have fallen on Earth. One possibility for this ee is the effect of antisymmetric components of the magnetic shielding tensor for 14N nuclei in amino acids, which in NMR manifests as the antisymmetric chemical shift (ACS). This can result in preferential destruction of their D-form through interactions with polarized leptons (e.g., …

Simulating Strongly Coupled Many-Body Systems With Quantum Algorithms, Manqoba Qedindaba Hlatshwayo

Dissertations

The complexity of the nuclear many-body problem is a severe obstacle to finding a general and accurate numerical approach needed to simulate medium-mass and heavy nuclei. Even with the advent of exascale classical computing, the impediment of exponential growth of the Hilbert space renders the problem intractable for most classical calculations. In the last few years, quantum algorithms have become an attractive alternative for practitioners because quantum computers are more efficient in simulating quantum physics than classical computers. While a fully fault-tolerant universal quantum computer will not be realized soon, this dissertation explores quantum algorithms for simulating nuclear physics suitable …

The Luminous Power Of Accretion Disks In Active Galactic Nuclei, Imogen Jade Courtney

Honors Theses

Active Galactic Nuclei (AGN) are the most luminous long-lived objects in the universe. The phenomenon of the immense luminosities we observe for AGN has interested physicists and astronomers for over a century and continues to fascinate scientists today. The work in this thesis aims to provide an introductory exploration of this phenomenon. This thesis uses a simple model of AGN accretion disks that was developed under the standard disk model proposed by Shakura & Sunyev in 1973 under the simplest assumptions. The model accurately demonstrates how physical parameters, such as the temperature, radiative flux, luminosity, and spectra, scale through an …

Time-Dependent Photoionization Modeling Of Warm Absorbers In Active Galactic Nuclei, Dev Raj Sadaula

Dissertations

Warm absorber spectra are bound-bound and bound-free absorption features, seen in the X-ray and UV spectra from many active galactic nuclei (AGN). The widths and centroid energies of these features indicate they occur in outflowing gas moving with hundreds to thousands of km/s. Depending upon the energy and momentum of the outflow, it can affect the gas within the host galaxy. Thus, warm absorbers’ mass and energy budgets are of great interest. Estimates for these properties depend on models that connect the absorption features' observed strengths with the density, composition, and ionization state of the absorbing gas. Such models assume …

Probing The Equation Of State Of Neutron Stars With Heavy Ion Collisions, Om Bhadra Khanal

Dissertations

The equation of state (EOS) is a fundamental property of nuclear matter, important for studying the structure of systems as diverse as the atomic nucleus and the neutron star. Nuclear reactions, especially heavy-ion collisions in the laboratories, can produce the nuclear matter similar to those contained in neutron stars. The density and the momentum dependence of the EOS of asymmetric nuclear matter, especially the symmetry energy term, is widely unconstrained. Finding appropriate constrains, especially at higher densities of the nuclear matter, requires the development of new devices, new experimental measurements as well as advances in theoretical understanding of nuclear collisions …

Studying The Synthesis Of 196Hg At Astrophysically Relevant Energies Through The Measurement Of Capture Reaction Cross-Sections Of (P, Γ) (P, N) And (P, Α) Reactions, Khushi Bhatt

Dissertations

Understanding the origin of all the chemical elements is an important question for the nuclear-astrophysics community. There are many unanswered questions like: What astrophysical events are responsible for the synthesis of what particular chemical elements? How many different elements were made in total? What is the abundance of each synthesized element? etc. Currently, scientists are largely depending upon theory and simulations to define nuclear and astrophysical reaction. This makes it critical to have accurate experimental nuclear physics data to input in astrophysical theoretical models. However, out of more than 20000 reactions involved in these calculations, only a very few are …

Study Of Deexcitation Intensities To The K-Shell In Iron 55, Eric Helgemo

Honors Theses

55Fe radioactive sources are used for x-ray calibration due to the long half-lives of 2.73 years and the optimal energies of the peaks. The source used in the experiment was generated using Western Michigan University’s Tandem Van de Graff accelerator to produce a 6 MeV proton beam which induced a 55Mn(p, n)55Fe reaction on a 10 μm 55Mn target. The emissions from this target were then measured using a silicon lithium drift x-ray detector to determine the number of instances of deexcitation through kα and kβ modes. The preliminary data discussed showed a lower relative deexcitation rate of 6.67 between …

Novel Low Temperature Properties Of Filled And Unfilled Single Crystal Irsb3, Matthew Cook

Dissertations

The skutterudite family of materials has garnered a lot of attention in the condensed matter community and it persists to be an important system for exploring the fundamental physics of solids. The initial interest into compounds with this common structure was due to their promising thermoelectric properties giving the possibility of efficient energy harvesting. Since, there has been a huge effort to systematically synthesize new filled skutterudite compounds, as nearly every type of strongly correlated behavior has been found within this family. As the field of topological materials has gained momentum, these materials have also been given a renewed interest …

Enhancement Of Critical Current In High-Temperature Superconductors By Ion Beam Irradiation Induced Defects, Prashanta Mani Niraula

Dissertations

Particle irradiation is used to induce defects in high-temperature superconducting Y₁Ba₂Cu₃O_7-x (YBCO) coated conductors, containing predominantly c-axis oriented barium zirconate (BZO) nanorods as pre-existing vortex pinning defects. Samples are irradiated with 50.0 MeV Cu ions with doses of 2.5 x 10¹², 2.0 x 10¹², 1.5 x 10¹², 1.0 x 10¹², 0.75 x 10¹², 0.5 x 10¹², 0.05 x 10¹² ions/cm². The dose of 0.5 x 10¹² ions/cm² is found to be the optimal dose with a …

Improving Lab Experience For Students In Phys2080, Khushi Bhatt

STEM Instructional Graduate Teaching Assistant Posters

University Physics II (PHYS 2080) deals with providing hands-on experience with the experiments of electricity and magnetism. It aids students to develop computational thinking in physics through analysis of experimental and theoretical data using python programming language.

In Fall-2019, I taught the newly designed PHYS2080 class for the first time as per the requirements. During Spring-2020, I implemented some subtle changes using the skills that I gained through various teaching training. These changes are described in Methodology section. Data clearly shows improvement that was observed without lowering the expectations or changing the curriculum of the class.

Issues And Proposed Solutions To Team Based Assessment In University Physics Labs, Manqoba Q. Hlatshwayo

STEM Instructional Graduate Teaching Assistant Posters

Many education experts considers peer-to-peer education as the most effective way for students to learn (Peersdom, 2014). Western Michigan University (WMU) physics laboratories embraces this philosophy and has designed the assessment to be based on the team report. The assumption is that every team member contributed (not necessarily equally) to the work submitted by the team hence every team member should receive the same grade. This is a ubiquitous assessment philosophy in education, and some forms of additional individual assessment in team projects are strongly discouraged (David Boud et al, 1999).

There is no doubt on the effectiveness of peer-to-peer …

Embedded Gold Nanoparticles For Metal Enhanced Photoluminescence, Hasna Alali

Dissertations

Noble metal nanoparticles (MNPs) have attracted great attention in electronics, solar cells and catalysis. Their unique optical properties and biocompatibility makes them useful in biological applications like imaging, drug delivery, therapy and diagnostic. At the surface of MNPs the collective oscillation of free electrons resonates with a particular wavelength of incident light, generating the Localized Surface Plasmons Resonance (LSPR). LSPR results in absorption and scattering of incident light. Scattering results in reflecting photons and absorption leads to enhanced photoluminescence and quenching of fluorophores, if the fluorophore is in the vicinity of MNPs.

Most of the studies in this regard have …

Investigation Of Finite Temperature And Continuum Effects On Nuclear Excitations, Herlik Wibowo

Dissertations

The low-energy nuclear response at finite-temperature significantly affects the radiative neutron capture reaction rates of the r-process nucleosynthesis. In order to address this topic, the first part of this study focuses on the response of compound nuclei or nuclei at finite temperature. The thermal nuclear response satisfies the Bethe-Salpeter equation (BSE) with the static and dynamical kernels of different origins. While the origin of the static kernel is the nearly instantaneous nucleon-meson interaction, the dynamical kernel is induced by the coupling between nucleons and phonons. The presence of singularities in the dynamical kernel makes the BSE unsolvable, however, a time …

Synthesis And Characterization Of Ion-Implanted Gold Nanoparticles, Nurlathifah Fnu

Masters Theses

Gold negative ions of 70 keV energy were implanted within the quartz substrates at room temperature at seven different fluences starting from 2 x 10¹⁶ particles/cm² to 8 x 10¹⁶ particles/cm² with the increment of 1 x 10¹⁶. Prior to the implantation, Stopping and Range of Ions in Matter (SRIM) calculations were carried to obtain the Bragg peak below the surface of quartz. Rutherford Backscattering Spectrometry (RBS) was carried out using 2.0 MeV He⁺⁺ ions to measure depth and implanted fluence of gold, and learn how they varied with fluence. Backscattered He particles …

Embedded Silver Nanoparticles For Metal Enhanced Photoluminescence, Shahid Iqbal

Dissertations

Imaging of biologically significant molecules using plasmons of Metal Nanoparticles (MNPs) is gaining attention in the research community. Localized Surface Plasmon Resonance (LSPR) is the coherent oscillation of conduction electrons of MNPs. The biologically significant molecule is labeled with the fluorophore molecule to get the image. This approach is widely used in clinical practices, however, low intensity light emission from the labeled molecule makes it difficult to image the biologically significant material. One way to improve the weak intensities of fluorophore is to enhance the brightness using a process called Metal Enhanced Photoluminescence (MEP). This phenomenon occurs in the close …

Simultaneous X-Ray Emission Accompanying Two Electron Capture For Fluorine On Gas Targets, David S. La Mantia

Dissertations

The collision between a charged ion and an atom resulting in the capture of two electrons, simultaneous with the emission of a single photon is referred to as radiative double electron capture (RDEC). For ion-atom collisions, this process can be considered the inverse of double photoionization. The study of either process, where just two electrons are involved without influence from neighboring electrons, promises new insight into electron correlation and the role it plays in quantum mechanics. Such a study for photoionization has not yet been done experimentally for two-electron ions because the only target system for which two electrons are …

Fostering Computational Thinking In An Introductory Physics Lab, Diana Sachmpazidi

STEM Instructional Graduate Teaching Assistant Posters

•Thinking computationally means conceptualizing a problem and formulating it in a way that a computer can solve it (Wing, 2010). •Computational Thinking (CT) is the third pillar of the scientific method along with theory and experimentation and is a fundamental skill that K-12 students and undergraduates should be equipped with (Wing, 2016; 2006). •Research on CT has only been active the last 10 years and most studies are still at the stage of ideas (Kalelioglu et al., 2016). •The integration of CT aspects in instruction is a widely expanding phenomenon in physics classrooms in the context of higher education, and …

Investigation Of Structural, Optical And Electronic Properties Of Modified Methylammonium Lead Iodide Perovskites, Rasanjali Jayathissa

Dissertations

Owing to their high-power conversion efficiency (PCE), easy processability, and low fabrication cost, organic lead halide perovskites (OLHP) are emerging as a most promising photovoltaic technology. However, toxicity of lead (Pb) is a major concern for further development. Therefore, it is essential to explore nontoxic metals to replace lead in these materials. In the current research work, nontoxic Mn²⁺, Na⁺ and Ba²⁺ are doped at 1, 5 and 10% mole concentrations to partially substitute Pb²⁺ in methyl ammonium lead iodide (CH₃NH₃PbI₃ or MAPbI₃) perovskite systems, and the effects …

Sensitivity Of The Theoretical Electron Capture Shape And Comparisons To Experiment, Katrina E. Koehler

Dissertations

The direct neutrino mass is a fundamental physics quantity with far-reaching implications for the physics community. Current experimental limits put the direct neutrino mass at less than 2 eV. The neutrino mass can be explored through an end-point measurement of tritium beta decay, which is currently underway in the KArlsruhe TRItium Neutrino experiment (KATRIN). KATRIN has a lower limit of 0.2 eV, at which point there will be either a mass measurement or another upper bound. In either case, an alternative experiment with different systematics is needed to verify the results and/or push the upper bound lower. The end point …

Radiative Double Electron Capture By Ions In Collisions With Gas Targets, Charles Taylor

Honors Theses

Radiative double electron capture (RDEC) is a two-step quantum process where two electrons are captured from the target gas to the projectile ion beam with a simultaneous emission of a single photon. The projectile ion beam was obtained from the tandem Van de Graaff accelerator at Western Michigan University. The projectile beam used is fully and partially ionized fluorine 9+, and 8+ in collision with highly pure nitrogen gas. The objective of the research is to observe RDEC from x ray detection using time to amplitude converters (TACs) that look for coincidences between x rays and particles. The signal from …

Radiative Double Electron Capture (Rdec) By Fully-Stripped Fluorine Ions In Collisions With Nitrogen, Nuwan Sisira Kumara

Dissertations

Radiative double electron capture (RDEC) by highly-stripped ions in collisions with atomic targets is a fundamental process that can be used to study electron-electron correlation, the interaction between two electrons, in the vicinity of the Coulomb field of a bare ion. In this process two electrons from the target are captured to bound states of the projectile with the simultaneous emission of a single photon. RDEC is closely related to the well-known one-step atomic process of radiative electron capture (REC), in which a target electron is captured to the projectile and a photon is simultaneously emitted. REC and RDEC can …

Department Of Physics Newsletter, Summer 2018, Department Of Physics

Physics Newsletter

• Message from Dr. Kirk Korista, Department Chair
• 2017 Alumni Achievement Award, Physics
• 2017 Solar Eclipse
• Department of Physics Award Ceremony

A 3d Simulation Of Leukocyte Adhesion In Blood Flow, Tai-Hsien Wu

Dissertations

It has been widely acknowledged that further understanding about the dynamics between blood cells and blood flow can help us gain more knowledge about the causes of diseases and discover more effective treatments. Examples of such dynamics include red blood cell (RBC, or erythrocyte) aggregation, white blood cell (WBC, or leukocyte) margination, and WBC extravasation. WBC extravasation is an important multiple-step process in the inflammatory response and therefore has drawn considerable attention over the past two decades. In this multiple-step process, a WBC undergoes at least four steps, including capture, rolling, firm adhesion, and transmigration, and each step is influenced …

The Proton Veto Project At Wmu/Msu, Justin Swaim

Honors Theses

The Proton Veto Wall (VW) is a charged particle detector designed and built at Western Michigan University for use at the National Superconducting Cyclotron Laboratory at Michigan State University. The VW assists the Large Area Neutron Array (LANA) with discriminating between charged particles detected via proton recoil in the scintillating material and charged particles detected from heavy ion collisions produced in the laboratory. Twenty five Eljen-200 plastic organic scintillators are arranged in a vertical position with photomultiplier tubes (PMTs) mounted to either end. The detector sits directly in front of LANA on a large stand that was assembled using T-slotted …