Physics Commons^™

Improved Momentum Spread For Precision Physics Experiments Using Wedges, Nick Amato

Graduate Research Theses & Dissertations

High precision experiments have become key in the search for physics beyond the Standard Model. One measurement that can be made in order to expand our knowledge of the Standard Model is the precise measurement of the magnetic dipole moment (MDM) of the muon. In order to perform this precise measurement of the MDM of muons, the storage of particles with a precisely known momentum in a highly uniform magnetic field is required.

This thesis is focused on how one may use a wedge of energy absorbing material and the optical parameters of an accelerator lattice to improve upon the …

Resonant Extraction For Mu2e, Prudhvi Raj Varma Chintalapati

Graduate Research Theses & Dissertations

Charged Lepton Flavor Violations (CLFVs) are probed in an attempt to search Beyond Standard Model (BSM) Physics. The sensitive channel available for experiments around the world is to probe through muons. No conclusive evidence of CLFV is found so far but $\mutoe$ experiment at Fermi National Accelerator Laboratory (Fermilab) aims to improve the current experimental sensitivity by searching for $\mu^{-}N \longrightarrow e^{-}N$ transition. To provide the high intensity beam that can be handled to achieve desired sensitivity, slow spill using resonant extraction is used at the accelerator complex.

Understanding the motivations behind the experiment and simulating the crucial stage in …

Study Of Higgs Production From H -> Zz -> 4l Channel Using Machine Learning Methods, Daniel Arthur Faia Jr.

Graduate Research Theses & Dissertations

In this thesis I will show how machine learning methods can improve on physics analysis in the H -> ZZ -> 4l channel. In particular we will explore how these methods can be used to classify Vector Boson Fusion (VBF) processes in the presence of more dominant Higgs production processes. The aim is to improve the ability to discriminate VBF Higgs boson production relative to other Higgs boson production modes. Since VBF has two quark jets in the final state, it is useful to discriminate between quark and gluon jets. We compare the effectiveness of quark gluon discrimination with machine …

Impact Of Standardized Test Performance On Success In Introductory College Physics Classes, Michael Gattone

Graduate Research Theses & Dissertations

This research project looks to analyze the ability of the ACT and other standardized tests to predict student success in introductory physics classes at Northern Illinois University (NIU). Admissions data from NIU was collected by the physics department from a total of 4262 students enrolled in introductory physics courses during the Fall 2012 semester until the Spring 2017 semester. This data includes academic level, gender, race/ethnicity, composite ACT score, high school GPA, and final letter grade. In particular, the composite ACT score of students was directly compared with their final letter grade from the student’s introductory physics class. The student …

Study Of Electron Beam Emitted From Nano-Structured Cathode, Anusorn Lueangaramwong

Graduate Research Theses & Dissertations

Over the years, particle accelerators have enabled breakthroughs in fundamental science while also becoming critical tools in medicine, homeland security, and societal applications. High-brightness electron beams are a key to the development of some of these accelerators and especially accelerator-based light sources. Electron emission is the first stage of the accelerator that dictates the ultimate beam brightness. To achieve such beam quality, electron sources--cathodes have been developed for their emission efficiencies. The cathodes with nanostructures on their surfaces have shown promising efficiencies when a laser pulse impinges, or an electric field is applied, on the cathode surface. Alternatively, these nano-patterned …

Towards Dual-Readout Calorimetry For Redtop Experiment, Tilak B. Malla

Graduate Research Theses & Dissertations

By virtue of peculiar properties of the eta (η) Goldstone boson, the study of it’s de-

cays is very important. The rare decays of this meson can provide unique opportunities

to probe several fundamental invariance principles of physics world. The REDTOP experi-

ment aims at searching for Physics Beyond Standard Model (BSM) by studying such decays

at a sensitivity of 10^ (−10) or below, which requires 10^ (12) or more η mesons. The REDTOP

collaboration has designed a detector to produce and reconstruct such a large number of

η mesons, which will make REDTOP a rare decay factory. The detector …

Direct Polymer Grafting As A Method Of Maintaining The Mechanical Properties Of Cellulose Nanocrystals In The Presence Of Moisture, Mary Elizabeth Breen-Lyles

Graduate Research Theses & Dissertations

Cellulose nanocrystals (CNCs) are a distinctive nanomaterial derived from cellulose, the most abundant natural polymer on Earth, and the primary reinforcing structural component of cellulose fibrils found within the plant cell wall. These nanocrystals exhibit mechanical properties comparable to synthetic aramid fibers but are advantageous as they are biodegradable, renewable, and can be produced sustainably as they are predominantly extracted from naturally occurring cellulosic materials. These qualities make it a sustainable, highly renewable and environmentally friendly material to be used in place of synthetic materials in a variety of applications. With their high surface area to volume ratio, low level …

Study Of The Systematic Uncertainties Associated With The Tracking Detectors, Daniel William Boyden

Graduate Research Theses & Dissertations

The muon g-2 experiment at Fermilab looks to measure the anomalous magnetic moment of the muon to an unprecedented precision of 0.14 ppm to verify results from the E821 experiment at Brookhaven National Laboratory. In addition to the anomalous magnetic moment of the muon the project also seeks to search for a muon electric dipole moment with a better precision than has previously has been achieved. These measurement along with standard model predictions may result in a discrepancy between the standard model and experimental results which may give some insight to beyond standard model physics.

This thesis will present the …

Magnetoresistance In Non-Magnetic Semimetals And Quantum Wells, Jing Xu

Graduate Research Theses & Dissertations

Magnetic field induced resistance change is conventionally termed as magnetoresistance (MR), which is usually related to magnetism and plays crucial roles in applications such as sensors and storage devices. In a single-band nonmagnetic material, the semiclassical Boltzmann equation approach gives rise to a magnetic field independent resistivity. With the recent discovery of topological materials, extremely large magnetoresistance (XMR) and negative longitudinal magnetoresistance (NLMR) have been observed in a variety of materials. In this dissertation I investigated XMRs in the rare-earth monopnictides (LaSb and YSb), which are non-saturating with increasing magnetic field, accompanying with a turn-on temperature behavior of the magnetoresistivity. …

Two-Dimensional Bloch Electrons In Electric And Magnetic Fields, Edward Aris Diaz Fajardo

Graduate Research Theses & Dissertations

Due to their extraordinary mechanical, and fascinating electronic properties, atomically flat two-dimensional materials are attractive avenues in the search for new and interesting physical phenomena. Symmetry is a powerful tool in studying the dynamics of Bloch electrons in these crystalline solids. Here, using a tight binding description, a systematic scheme is developed to derive the symmetry labels, called irreducible representations (IRs), characterizing the Bloch eigenstates in a crystal, including an extensive discussion on the possibility that these IRs are not always unique. This theory is illustrated using monolayer MoS$_2$ and few-layer graphene as examples. Using this symmetry analysis in conjunction …

Thermal Analysis And Design Of Conduction Links For A Superconducting Radio Frequency Resonator, Aaron Mckeown

Graduate Research Theses & Dissertations

The SRF conduction link project at Fermi National Accelerator Laboratory aims to develop an SRF particle accelerator design that is more applicable for industrial use. Collaboration between NIU college of engineering and NIU department of physics provided the bulk of design and analysis for this project. Currently, cooling systems, used in SRF particle accelerators, pump liquid helium across the SRF cavity to provide convection based cooling. The goal of this project is to incorporate a conduction based cooling system. In a conduction based cooling system, heat will flow from the SRF cavity into a cryocooler through a conduction link. In …

Magnetotransport In Zrte5 Crystals, Maksim Andreevich Sultanov

Graduate Research Theses & Dissertations

ZrTe5 is a topological material that is predicted to have a strain or temperature induced phase transition from a topological insulator state into a Weyl/Dirac semimetal state. In this study I find that there is insufficient evidence to support the claims for the existence of such a phase transition. I performed magnetoresistivity measurements using a Quantum Design Physical Properties Measurement System (PPMS) to measure the transverse and longitudinal resistivities at various temperatures and different strengths and orientations of the magnetic field. The measurement results were analyzed using OriginPro to determine the carrier mobility and density and to determine the temperature …