Physics Commons^™

The Design Of Primary Holding Magnet For The Lanl Neutron Electric Dipole Moment Experiment, Piya Amara Palamure

Theses and Dissertations--Physics and Astronomy

The measurement of the permanent electric dipole moment of the neutron (nEDM) plays a significant role in searching for sources of beyond standard model CP violating physics. The goal of the Los Alamos National Laboratory (LANL) nEDM experiment is to push the upper limit of the nEDM to < 3 × 10−27 e·cm (68 % CL). A highly uniform magnetic field is key to achieving this sensitivity for the nEDM measurement by reducing the systematic uncertainties associated with the magnetic field non-uniformity. The B0 coil was designed to achieve a field uniformity of < 0.3 nT·m−1 at a nominal holding field of 1 µT. This document will outline a novel technique employed in the construction of the B0 coil using printed circuit boards (PCBs) and will present preliminary field maps obtained with the B0 coil housed in a magnetically shielded room (MSR) at LANL.

As Ultra Cold Neutrons (UCNs) move from the source to the measurement cells, the UCNs experience a large magnetic field gradient in the region between the layers of the MSR. This large gradient would otherwise cause depolarization of the UCNs. To mitigate this, a double cos θ coil will serve as the …

Design Of The Highly Uniform Magnetic Field And Spin-Transport Magnetic Field Coils For The Los Alamos National Lab Neutron Electric Dipole Moment Experiment, Jared Brewington

Theses and Dissertations--Physics and Astronomy

Charge-Parity (CP) violation is one of Sakharov's three conditions which serve as guidelines for the generation of a matter-antimatter asymmetry in the early universe. The Standard Model (SM) of particle physics contains sources of CP violation which can be used to predict the baryon asymmetry. The observed baryon asymmetry is not predicted from SM calculations, meaning there must be additional sources of CP violation beyond the Standard Model (BSM) to generate the asymmetry. Permanent electric dipole moments (EDMs), which are inherently parity- and time reversal- violating, present a promising avenue for the discovery of new sources of CP violation to …

Stratospheric Glider Measurements Of Atmospheric Parameters, Anisa Haghighi

Theses and Dissertations--Mechanical Engineering

In June 2021 a series of high altitude flights were conducted in Spaceport America, NM, using a balloon launched Uncrewed Aircraft System (UAS) to assess its capability to conduct measurements of various atmospheric properties and study turbulence in the troposphere and lower stratosphere. This UAS descends using an automated flight trajectory. The instruments aboard included a NASA-developed infrasonic microphone to evaluate its remote turbulence detection capabilities and a five-hole probe capable of measuring the in situ wind vector. Also on board were temperature, humidity and wind profile sensors. This document focuses on the atmospheric properties measured at high altitudes, the …

Beam Dynamics Simulations And Systematic Studies For The Muon G-2 Experiment At Fermilab, Abel M. Lorente Campos

Theses and Dissertations--Physics and Astronomy

The first results of the positive muon anomalous magnetic moment from the Muon g-2 Experiment at Fermilab differs from the Standard Model prediction by 3.3 standard deviations, with an experimental uncertainty of 0.46 ppm. Combining this result with the previous measurement from the Brookhaven National Laboratory, it sets the difference between experiment and theory at 4.2 standard deviations. The goal of the Muon g-2 Experiment at Fermilab is to increase this discrepancy to 5 standard deviations, which would require unprecedented precision in the measurements of 0.14 ppm. Of significant importance to achieving this precision, beam and spin dynamics simulations are …

Measurements Of The Binding Energies Of Ions On Plastic Surfaces In Liquid Nitrogen, Ashok Timsina

Theses and Dissertations--Physics and Astronomy

To improve the present limit of the neutron electric dipole moment (nEDM) from 1.8*10^-26 e. cm to ~ 3*10^-28 e. cm, the nEDM@SNS experiment plans to increase neutron density by storing ultracold neutrons in superfluid helium-4. In this experiment, the central part of the apparatus consists of two deuterated tetraphenyl butadiene (dTPB) coated poly(methyl methacrylate) (PMMA) cells, which are sandwiched between grounded and high-voltage electrodes. To achieve such precision, the externally applied electric field has to be stable at the 1% level over a time period of about 1000 s. Several sources of ambient ionizing radiation generate charged …

Aspects Of Topology In Moiré Graphene, Ahmed Khalifa

Theses and Dissertations--Physics and Astronomy

Moiré materials, such as twisted bilayer graphene, have provided a rich platform for fundamental physics and potential technological applications. Superconductivity,
correlated insulators, and Chern insulators are examples of phenomena that have been found experimentally in moiré systems. The interplay of strong electron-electron interactions and topology lies at the heart of the mechanism driving these phenomena. In this work, we study the topological aspects of moiré graphene materials, such as the valley Chern and Chern insulating phases. To study the topological response of these phases, we construct models to describe the edge states which are the telltale signs of nontrivial topology. …

Symbolic Computation Of Squared Amplitudes In High Energy Physics With Machine Learning, Abdulhakim Alnuqaydan

Theses and Dissertations--Physics and Astronomy

The calculation of particle interaction squared amplitudes is a key step in the calculation of cross sections in high-energy physics. These complex calculations are currently performed using domain-specific symbolic algebra tools, where the computational time escalates rapidly with an increase in the number of loops and final state particles. This dissertation introduces an innovative approach: employing a transformer-based sequence-to-sequence model capable of accurately predicting squared amplitudes of Standard Model processes up to one-loop order when trained on symbolic sequence pairs. The primary objective of this work is to significantly reduce the computational time and, more importantly, develop a model that …

Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical Engineering

Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …

Neutron Stars With Baryon Number Violation, Probing Dark Sectors, Jeffrey M. Berryman, Susan Gardner, Mohammadreza Zakeri

Physics and Astronomy Faculty Publications

The neutron lifetime anomaly has been used to motivate the introduction of new physics with hidden-sector particles coupled to baryon number, and on which neutron stars provide powerful constraints. Although the neutron lifetime anomaly may eventually prove to be of mundane origin, we use it as motivation for a broader review of the ways that baryon number violation, be it real or apparent, and dark sectors can intertwine and how neutron star observables, both present and future, can constrain them.

Atomistic Engineering Of Phonons In Functional Oxide Heterostructures, Seung Gyo Jeong, Ambrose Seo, Woo Seok Choi

Physics and Astronomy Faculty Publications

Engineering of phonons, that is, collective lattice vibrations in crystals, is essential for manipulating physical properties of materials such as thermal transport, electron-phonon interaction, confinement of lattice vibration, and optical polarization. Most approaches to phonon-engineering have been largely limited to the high-quality heterostructures of III–V compound semiconductors. Yet, artificial engineering of phonons in a variety of materials with functional properties, such as complex oxides, will yield unprecedented applications of coherent tunable phonons in future quantum acoustic devices. In this study, artificial engineering of phonons in the atomic-scale SrRuO₃/SrTiO₃ superlattices is demonstrated, wherein tunable phonon modes are observed …

Elastic And Inelastic Compton Scattering From Deuterium At 61 Mev, Danula Godagama

Theses and Dissertations--Physics and Astronomy

A Compton scattering experiment using deuteron as target nuclei was carried out at the HIγS free electron laser facility at Durham, NC, with the goal of extracting the electromagnetic scalar polarizabilities of the neutron, α_n and β_n. A beam of 61~MeV gamma photons with a narrow energy spread was incident on a liquid deuterium target. The scattered gamma rays were detected at three scattering angles, 55^o, 115^o and 150^o. Backward-scattered gamma rays were detected using two large-volume NaI spectrometers with energy resolution (σ_E/E) better than 2%. The combined effect of …

Studies Of Time Variations Of The Magnetic Field In The Nedm@Sns Experiment, Mojtaba Behzadipour

Theses and Dissertations--Physics and Astronomy

It is thought that equal quantities of matter and antimatter were generated at the moment of the Big Bang. However, observations of the Universe show that there is a significant excess of matter over antimatter. The matter-antimatter asymmetry in the Universe (baryon to photon ratio) is observed to be of the order of 10^-10 [1]. Baryogenesis is a possible explanation for the matter-antimatter asymmetry of the universe. In 1967, Sakharov proposed three criteria necessary for Baryogenesis. The three conditions are: 1) baryon number violation, 2) C and CP violation and 3) departure from thermal equilibrium. However, the Standard Model's …

Investigating The Uncertainties In Ct Non-Small Cell Lung Cancer Radiomics, Gary Ge

Theses and Dissertations--Radiation Medicine

Radiomics is a technique that extracts quantitative features, termed radiomic features, from medical images using data-characterization algorithms. These radiomic features can be used to identify tissue characteristics and radiologic phenotyping that are not observable by clinicians in a non-invasive, low-cost manner, potentially generating image biomarkers for clinical decision. To date, there are still many uncertainties involved in radiomics which limit its clinical implementation. Herein, we propose to explore the impact of each component in the radiomics pipeline on predicting clinical outcomes. In Chapter II, we conduct a thorough review of CT lung cancer radiomics studies to examine the typical feature …

Angular Distribution Of Electron-Helium Scattering In The Presence Of A 1.17 Ev Laser Field, Brian N. Kim

Theses and Dissertations--Physics and Astronomy

We have measured relative differential cross sections for 350 eV electrons scattered by a helium target in the presence of 1.17 eV photons from an Nd:YAG laser. We report an angular distribution of free-free electrons that were scattered elastically at angles between 15^o and 80^o and of free-free electrons that underwent the process of electron-impact excitation of helium to its unresolved (1s2s)¹S and (1s2p)¹P excited states at angles between 1^o and 80^o. Our experiments test the momentum transfer dependence and the relationship between elastic and inelastic scattering in the Kroll-Watson approximation. …

An Energy-Integrated Analysis For Measuring The Anomalous Precession Frequency For The Muon G − 2 Experiment At Fermilab, Laura Kelton

Theses and Dissertations--Physics and Astronomy

In the search for physics beyond the Standard Model, the Muon g − 2 Experiment at Fermilab (E989) will make the most precise measurement of the anomalous magnetic moment of the muon, a_μ. Improvements in precision come from both increased statistics and new techniques to significantly reduce previous systematic uncertainties. The muon a_μ is determined by extracting both the anomalous spin precession frequency, ω_a, and the average magnetic field sampled by the muons, B. Traditionally an energy threshold analysis method which requires reconstruction of decay positrons from the muon decay, μ⁺ → e^{+ …}

Cryogenic Magnetic Field Monitoring System In The Sns Neutron Edm Experiment, Umit Hasan Coskun

Theses and Dissertations--Physics and Astronomy

A permanent neutron electric dipole moment (nEDM), d_n, would violate charge-conjugation and parity (CP) symmetry. The neutron electric dipole moment currently has a global limit of d_n < 1.8 x 10^-26 e cm (90% CL). This limit is intended to be improved by two orders of magnitude by the nEDM experiment at the Spallation Neutron Source (SNS nEDM), d_n ~ 10^-28 e cm. The magnetic field non-uniformities within the experimental region must be precisely monitored and managed in order to suppress systematic effects in the experiment caused by magnetic field gradients. The estimation of magnetic field components within …

Extraction Of Deep Inelastic Cross Sections Using A 10.4 Gev Electron Beam And A Polarized Helium-3 Target, Murchhana Roy

Theses and Dissertations--Physics and Astronomy

Experiment E12-06-121 at Jefferson Lab aims to do a precision measurement of the neutron spin structure function g₂ using inclusive inelastic scattering of electrons over a large kinematic range of x and Q². The third moment of the linear combination of the spin structure functions g₁ and g₂, d₂, is one of the cleanest higher twist observables and contains information on quark-gluon correlations. It is connected to the "color polarizability" or "color Lorentz force" of the nucleon. The experimental data taking was successfully conducted in Hall C using a longitudinally polarized electron …

Thermalization And Quantum Information In Conformal Field Theory, Ashish Kakkar

Theses and Dissertations--Physics and Astronomy

The consequences of the constraints of conformal symmetry are far-reaching within
theoretical physics. In this dissertation we address a series of questions in conformal
field theory: 1) We calculate the spectrum of qKdV charges in a large central charge
expansion. 2) We determine the corrections to bulk information geometry from 1/N
contributions to holographic correlators. 3) We study the higher genus partitions
functions of CFTs associated with classical and quantum error-correcting codes.

High Performance Data Acquisition And Analysis Routines For The Nab Experiment, David Mathews

Theses and Dissertations--Physics and Astronomy

Probes of the Standard Model of particle physics are pushing further and further into the so-called “precision frontier”. In order to reach the precision goals of these experiments, a combination of elegant experimental design and robust data acquisition and analysis is required. Two experiments that embody this philosophy are the Nab and Calcium-45 experiments. These experiments are probing the understanding of the weak interaction by examining the beta decay of the free neutron and Calcium-45 respectively. They both aim to measure correlation parameters in the neutron beta decay alphabet, a and b. The parameter a, the electron-neutrino correlation coefficient, is …

Enhancements To Uniformity Of Magnetic Fields At The Sns Nedm Experiment, Ahmad Saftah

Theses and Dissertations--Physics and Astronomy

The nEDM experiment at the Spallation Neutron Source (SNS) aims to increase
experimental sensitivity to hadronic CP violation by nearly two orders of magnitude.To do that the nEDMSNS experiment requires an extremely uniform magnetic field to maintain ³He polarization during transit to the measurement cell. The Magnetic Shield Enclosure (MSE) coil provides the required field. However, the superconducting shield distorts the MSE field.

This thesis discusses a magnetic cloak for the nEDM@SNS experiment that can restore the MSE field uniformity and cos theta coils designed to test the magnetic cloak in the first part. The second part of this …

Understanding The Degradation Mechanism In Methyl Ammonium Lead Halide Perovskite And Black Phosphorene Via Electrical Transport Study, Huda Saleh Aljeailan

Theses and Dissertations--Physics and Astronomy

This work seeks to understand the degradation mechanism of technically important material systems such as black phosphorene (BP), arsenic phosphorene (AsP) and Methyl ammonium lead iodide (CH₃NH₃PbI₃) perovskite. Degradation studies were conducted by studying the in-situ electrical transport properties (resistance and thermoelectric power (TEP)) of these materials in vacuum (under annealed condition) and after exposure to the ambient air.

BP and both exhibited p-type semiconducting (positive TEP) behavior under annealed conditions and the changes in their transport properties upon exposure to ambient air can be explained as due to the charge transfer between the …

Neutron Spectroscopy Of The Parity-Violating 0.734 Ev Neutron Resonance In Lanthanum-139 In Preparation For The Noptrex Time Reversal Violation Experiment, Danielle Schaper

Theses and Dissertations--Physics and Astronomy

One of the most outstanding questions in physics is the matter-antimatter asymmetry of the Universe, resulting from excess baryogenesis processes during the early moments of the formation of the Universe. At present, the types of processes needed to explain this matter excess, so-called `CP-violating processes' are known to exist within the present framework of the Standard Model of particle physics. However, decades of research has shown that our understanding of the origin of these processes is incomplete, as we do not presently know of enough sources of CP-violating processes to account for the large baryon asymmetry that we observe. The …

Magnetization Dynamics In A Modified Square Artificial Spin Ice, Amrit Kaphle

Theses and Dissertations--Physics and Astronomy

Artificial spin ices are magnetic metamaterials consisting of nanomagnet arrays in a 2-D lattice. Typically, these nanomagnet arrays are binary macrospins that can only be in an up or down state similar to the Ising spins. They have been intensively used to study magnetic frustration and ordering phenomena in a controlled environment. The hexagonal artificial spin ice and square artificial spin ice are among the most heavily studied systems. In this dissertation, we designed a modified square artificial spin ice system by an ordered substitution of a double-segment for a nanomagnet array in the unit cell of square artificial spin …

Data Acquisition, Analysis And Simulations For The Fermilab Muon G−2 Experiment, Fang Han

Theses and Dissertations--Physics and Astronomy

The goal of the new Muon g-2 E989 experiment at Fermi National Accelerator Laboratory (FNAL) is a precise measurement of the muon anomalous magnetic moment, a_μ ≡ (g-2)/2. The previous BNL experiment measured the anomaly a_μ(BNL) with an uncertainty of 0.54 parts per million (ppm). The discrepancy between the current standard model calculation of the a_μ(SM) and the previous measurement a_μ(BNL) is over 3σ. The FNAL Muon g-2 experiment aims at increasing the precision to 140 parts per billion (ppb) to resolve the discrepancy between the theoretical …

Energy Integrated Ratio Analysis Of The Anomalous Precession Frequency In The Fermilab Muon G-2 Experiment, Ritwika Chakraborty

Theses and Dissertations--Physics and Astronomy

The muon’s anomalous magnetic moment, a_μ, provides a unique way for probing physics beyond the standard model experimentally as it gathers contributions from all the known and unknown forces and particles in nature. The theoretical prediction of a_μ has been in greater than 3 σ tension with the experimental measurement since the results of the Muon g-2 Experiment at the Brookhaven National Laboratory (E-821) were published in the early 2000s with a precision of 540 ppb. To settle this tension, the new Fermilab Muon g - 2 Experiment (E-989) is currently taking data with the aim of …

Scale Model Equations And Optimization For Annular Flow Of Non-Newtonian Fluids Between Eccentric And Rotating Cylinders, Wei Zhang, Pooya Khodaparast, Amin Mehrabian Dr., Amir Shojaei

Progress in Scale Modeling, an International Journal

A broad range of engineering applications involves helical flow of non-Newtonian fluids between two eccentric cylinders. These applications often require estimation of the frictional pressure losses along the axes of the cylinders. Laboratory flow loops are commonly used to study the flow characteristics at smaller scales of investigation. This study uses the laws of similarity and dimensional analysis to obtain a set of scaling equations between the laboratory and prototype scales of the described annular flow. These equations are derived for four types of fluid rheology including Newtonian, power-law, Bingham-plastic, and yield power-law.

Results are expressed through a set of …

Comments On The Holographic Description Of Narain Theories, Anatoly Dymarsky, Alfred D. Shapere

Physics and Astronomy Faculty Publications

We discuss the holographic description of Narain U(1)^c × U(1)^c conformal field theories, and their potential similarity to conventional weakly coupled gravitational theories in the bulk, in the sense that the effective IR bulk description includes “U(1) gravity” amended with additional light degrees of freedom. Starting from this picture, we formulate the hypothesis that in the large central charge limit the density of states of any Narain theory is bounded by below by the density of states of U(1) gravity. This immediately implies that the maximal value of the spectral gap for primary fields is ∆₁ = …

The Measure Aspect Of Quantum Uncertainty, Of Entanglement, And The Associated Entropies, Ivan Horváth

Physics and Astronomy Faculty Publications

Indeterminacy associated with the probing of a quantum state is commonly expressed through spectral distances (metric) featured in the outcomes of repeated experiments. Here, we express it as an effective amount (measure) of distinct outcomes instead. The resulting μ-uncertainties are described by the effective number theory whose central result, the existence of a minimal amount, leads to a well-defined notion of intrinsic irremovable uncertainty. We derive μ-uncertainty formulas for arbitrary set of commuting operators, including the cases with continuous spectra. The associated entropy-like characteristics, the μ-entropies, convey how many degrees of freedom are effectively involved in a given …

Awegnn: Auto-Parametrized Weighted Element-Specific Graph Neural Networks For Molecules., Timothy Szocinski, Duc Duy Nguyen, Guo-Wei Wei

Mathematics Faculty Publications

While automated feature extraction has had tremendous success in many deep learning algorithms for image analysis and natural language processing, it does not work well for data involving complex internal structures, such as molecules. Data representations via advanced mathematics, including algebraic topology, differential geometry, and graph theory, have demonstrated superiority in a variety of biomolecular applications, however, their performance is often dependent on manual parametrization. This work introduces the auto-parametrized weighted element-specific graph neural network, dubbed AweGNN, to overcome the obstacle of this tedious parametrization process while also being a suitable technique for automated feature extraction on these internally complex …

The Design Of The N2edm Experiment, N. J. Ayres, G. Ban, L. Bienstman, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, E. Chanel, J. Chen, P.-J. Chiu, B. Clément, C. B. Crawford, M. Daum, B. Dechenaux, C. B. Doorenbos, S. Emmenegger, L. Ferraris-Bouchez, M. Fertl, A. Fratangelo, P. Flaux

Physics and Astronomy Faculty Publications

We present the design of a next-generation experiment, n2EDM, currently under construction at the ultracold neutron source at the Paul Scherrer Institute (PSI) with the aim of carrying out a high-precision search for an electric dipole moment of the neutron. The project builds on experience gained with the previous apparatus operated at PSI until 2017, and is expected to deliver an order of magnitude better sensitivity with provision for further substantial improvements. An overview is of the experimental method and setup is given, the sensitivity requirements for the apparatus are derived, and its technical design is described.