Physical Sciences and Mathematics Commons^™

Novel Technique Using Cherenkov Radiation For Nuclear Terrorism Prevention, Matthew Mark Romano

Aerospace, Physics, and Space Science Student Publications

I present a novel approach for detecting rogue nuclear material at country borders, addressing the current lack of reliable and economical mechanisms for this purpose. My proposed methodology utilizes Cherenkov radiation emitted by cosmic muons to reconstruct the particle's trajectory using a single detector. By analyzing the eccentricity of the projected ellipse formed when the Cherenkov cone intersects the detector plane, one can determine the angle a muon makes with the detector. This innovative technique effectively doubles the efficiency of the detection system by halving the number of required detectors while simultaneously increasing the resolution of the measurements taken.

Fabrication, Measurements, And Modeling Of Semiconductor Radiation Detectors For Imaging And Detector Response Functions, Corey David Ahl

Doctoral Dissertations

In the first part of this dissertation, we cover the development of a diamond semiconductor alpha-tagging sensor for associated particle imaging to solve challenges with currently employed scintillators. The alpha-tagging sensor is a double-sided strip detector made from polycrystalline CVD diamond. The performance goals of the alpha-tagging sensor are 700-picosecond timing resolution and 0.5 mm spatial resolution. A literature review summarizes the methodology, goals, and challenges in associated particle imaging. The history and current state of alpha-tagging sensors, followed by the properties of diamond semiconductors are discussed to close the literature review. The materials and methods used to calibrate the …

Total Absorption Spectroscopy Of Mo-106 And Tc-106, Michael Cooper

Doctoral Dissertations

Total absorption spectroscopy is a method of gamma-ray spectroscopy that has gained prominence in the past several decades, as nuclear data revisions are performed on older nuclear data, which is often incomplete. A strong understanding of underlying nuclear data, particularly fission and beta decay data, is essential for nuclear reactors and nuclear fuel decay heat. This PhD work involves the analysis of fission fragments 106Mo [Mo-106] and 106Tc [Tc-106]. These neutron rich isotopes contribute upwards of 6% of the cumulative fission yield of 241Pu [Pu-241] fission, and 4% of 239Pu [Pu-239] fission. Prior data for these two fission fragments only …

Muon Intensity Measurement With The Majorana Demonstrator, Franklin Michael Adams Jr.

Theses and Dissertations

The Majorana Demonstrator (MJD) is a shielded radiation detection system located a mile underground at the Sanford Underground Research Facility (SURF) in South Dakota. The system aims to detect the theorized, rare process of neutrinoless double-beta decay. The Demonstrator utilizes an array of scintillating acrylic detectors to veto any signals induced by earth-penetrating cosmogenic muons and reach background levels necessary for the detection of neutrinoless double-beta decay. Utilizing the data collected by the muon veto system, an analysis has been done to determine the differential muon intensity. The complex geometry of the interlacing detector panels requires the use of Monte …

Characterization Of Deposited Copper Oxide Films On Copper Substrates, Millicent Castillo

Electronic Thesis and Dissertation Repository

The deposition of copper oxide films on copper substrates was investigated by the electrochemical, thermal, and hydrothermal oxidation of copper. The formed oxides were characterized using various surface analytical techniques to determine the film’s morphology, composition, and thickness. The results show that by growing oxides electrochemically, a duplex layer composing of CuO and Cu₂O film was formed on the copper surface, having characteristics of being porous and possessing needle-like structures. An oxide film composed of CuO and Cu₂O, which shows minimal porosity and possess mixtures of crystalline and non-crystalline structures, is formed on the copper surface …

Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan

LSU Doctoral Dissertations

Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to ⁴⁰Ca. In ONe novae, the incompletely understood reaction rate of ³⁰P(p,γ)³¹S is known to strongly influence the production rate of several stable isotopes such as ³⁰Si, ³¹P, and ^32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …

Study Of The Etaprimepi0 System In Gluex, Rupesh Dotel

FIU Electronic Theses and Dissertations

The η′π is an important decay channel for the potentially exotic hybrid meson π1(1600) that has been detected in the COMPASS, VES and E852 experiments. These previous experiments used a charged pion beam as a probe. In contrast, the GlueX experiment is designed to search for the exotic hybrid mesons using a linearly polarized photon beam. This thesis project analyzes the η′π0 system produced in GlueX by the reaction γp → η′π0p. After optimizing the event selection to minimize background contributions, a mass independent partial wave analysis is performed in search of an exotic signature. Within the currently available statistical …

Enigma - Ongoing Development Towards Novel Beta-Decay Spectroscopy Station At Isolde, Philipp Wagenknecht

Masters Theses

Beta decay and collinear laser spectroscopy are proven efficient tools to study nuclear structure far from stability. Two areas of significance are investigations into nuclear deformation and shape coexistence, as well as delayed neutron emissions used in nuclear energy applications. This contribution presents the ongoing development towards a novel beta-decay spectroscopy station for the VITO experiment at CERN’s radioactive ion beam facility ISOLDE. The setup will utilize both collinear laser spectroscopy and beta-decay spectroscopy to measure the energy and spin-parities of the ground and excited states of radioactive beams. Initial designs of the support structure, magnetic field, and detector array …

Investigating Gluonic Operators In Coordinate Space, Wayne Henry Morris Iii

Physics Theses & Dissertations

In this dissertation, a method of extracting gluon momentum distributions inside hadrons, and particularly nucleons, is developed. In general, the utility and application of performing calculations in coordinate space at the operator level is discussed, and its application to the method of pseudodistributions in the lattice extraction of parton distributions. An introduction to the background field method and other techniques used in the calculation of corrections to gluon operators are provided. Then, an outline of the calculation of the uncontracted gluon bilocal operator at one-loop is given, and the result thereof. Using the result for the gluon bilocal operator restricted …

Jet Substructure Measurements In Proton-Proton And Proton-Gold Collisions, Isaac Arthur Mooney

Wayne State University Dissertations

Observing a modification of high-energy probes in the hot nuclear environment created by ultrarelativistic heavy-ion collisions is critical for understanding the microscopic structure of the QCD medium. However, before a modification can be observed, the probes must be calibrated. For this reason, measurements of jet observables in vacuum (pp collisions) and in the presence of cold nuclear matter (pAu collisions) are presented, which will allow for future comparison of jet substructure measurements in AuAu to these baseline measurements. \parData from the STAR detector on the Relativistic Heavy Ion Collider at Brookhaven National Laboratory are used for both analyses. The pp …

Particle Swarm Optimization For Critical Experiment Design, Cole Michael Kostelac

Masters Theses

“Critical experiments are used by nuclear data evaluators and criticality safety engineers to validate nuclear data and computational methods. Many of these experiments are designed to maximize the sensitivity to a certain nuclide-reaction pair in an energy range of interest. Traditionally, a parameter sweep is conducted over a set of experimental variables to find a configuration that is critical and maximally sensitive. As additional variables are added, the total number of configurations increases exponentially and quickly becomes prohibitively computationally expensive to calculate, especially using Monte Carlo methods.

This work presents the development of a particle swarm optimization algorithm to design …

Nuclear Transparency From Quasi-Elastic $^{12}C(E,E'P)$ Scattering Reaction Up To $Q^2=14.2 ~(Gev/C)^{2}$ In Hall C At Jefferson Lab, Deepak Kumar Bhetuwal

Theses and Dissertations

Color Transparency $(CT)$ is a unique prediction of Quantum Chromodynamics $(QCD)$ where the final (and/or initial) state interactions of hadrons with the nuclear medium are suppressed for exclusive processes at high momentum transfers. While this phenomenon has been observed for mesons, there has never been a conclusive observation for baryons. A clear signal of $CT$ for baryons would be the first evidence of baryons fluctuating to a small size in the nucleus, and the onset would show the transition from nucleon-meson picture to quark-gluon degrees of freedom. The experiment $E1206107$, searching for the onset of $CT$ in protons was completed …

Single-Neutron States In 51ti Via Neutron Transfer Reaction To 50ti, Jessica Nebel-Crosson

Physics and Astronomy Honors Papers

My project clarifies previous measurements made for the high excitation states of titanium isotopes, specifically ⁵¹Ti. We used a single-neutron transfer reaction from a deuterium source and measured the energy difference between the initial energy of the deuterium source, the transferred neutron, and the free proton. Our analysis included creating angular distribution plots of the proton momentum and the loose assignments of the single-particle state nature for each excitation state. We took these measurements via the Super-Enge Split-Pole Spectrograph at Florida State University.

Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data, R. Weiss, A. W. Denniston, J. R. Pybus, O. Hen, E. Piasetzky, A. Schmidt, L. B. Weinstein, N. Barnea

Physics Faculty Publications

The extraction of the relative abundances of short-range correlated (SRC) nucleon pairs from inclusive electron scattering is studied using the generalized contact formalism (GCF) with several nuclear interaction models. GCF calculations can reproduce the observed scaling of the cross-section ratios for nuclei relative to deuterium at high x_B and large Q², a₂ = (σ_A/A)/(σ_d/2). In the nonrelativistic instant-form formulation, the calculation is very sensitive to the model parameters and only reproduces the data using parameters that are inconsistent with ab initio many-body calculations. Using a light-cone GCF formulation significantly decreases this sensitivity …

Equations Of State For Warm Dense Carbon From Quantum Espresso, Derek J. Schauss

Theses and Dissertations

Warm dense plasma is the matter that exists, roughly, in the range of 10,000 to 10,000,000 Kelvin and has solid-like densities, typically between 0.1 and 10 grams per centimeter. Warm dense fluids like hydrogen, helium, and carbon are believed to make up the interiors of many planets, white dwarfs, and other stars in our universe. The existence of warm dense matter (WDM) on Earth, however, is very rare, as it can only be created with high-energy sources like a nuclear explosion. In such an event, theoretical and computational models that accurately predict the response of certain materials are thus very …

Strategies To Control Costs At U.S. Commercial Nuclear Power Plants, Gregory J. Lindamood

Walden Dissertations and Doctoral Studies

Commercial nuclear power plants in the United States are not cost competitive because of high operating and maintenance costs and historically low natural gas prices, resulting in the potential for premature plant closure of up to 25% of the operating power plants by 2025. Premature plant closure could impact the consumer through higher electricity rates, increased air pollution, and electric grid instability from increased renewable usage. Grounded in the behavioral decision theory, the purpose of this qualitative single case study was to explore successful strategies nuclear leaders used to control costs and ensure competitiveness. Data were collected through semistructured interviews …

Finding And Analyzing U235 And U238 Ternary Fission Events In The Niffte Fissiontpc, Gabriel A. Oman

Physics

In this analysis, the differences between ternary and binary fission were explored using data from the NIFFTE Collaboration’s fission time projection chamber (TPC). The ratio of binary-to-ternary events for U-235 and U-238 as a function of neutron kinetic energy in the range of 1-30 MeV is presented. The typical value of the ratio is approximately 105 binary fissions per ternary fission, in agreement with previously published measurements. Future work will involve distinguishing the fissions of the two isotopes to provide more insight into this rare process.

Preparation And Evaluation Of Uranium Alloys Based On Burnup, Andrew Jonathan Swift

UNLV Theses, Dissertations, Professional Papers, and Capstones

Next generation fast reactor designs utilizing metallic fuel are being developed as an alternative fuel cycle option in an effort to reduce carbon emissions. Historically, oxide fuels have been the industry standard, but interest in metallic fuel systems has grown considerably due to their thermal conductivity, fissile atom density, inherent safety, and ability to reach progressively higher burnups. Chemical complexity of metallic fuel systems increase as a function of burnup from fission product ingrowth and associated fuel cladding chemical interactions (FCCI) brought on by elemental redistribution and phase formation. To date, the most extensive operational study for metallic fuel was …

Polarization Observables For Γp −> K+Λ At Photon Energies Up To 5.45 Gev, Shankar Dayal Adhikari

FIU Electronic Theses and Dissertations

Excited nucleon states are established as an important milestone to understand quantum chromodynamics in the non-perturbative region. Even after decades of study, not all of the excited states predicted by different theoretical approaches have been verified. The disparity between the predicted states and the verified states is known as the “missing baryon problem". The verified states were mostly established using pion beam data or through Nπ decay channels, but are not sufficient to address the missing baryon problem. In recent years, new experiments were conducted worldwide at CLAS in Jefferson Lab, ELSA in Bonn, MAMI in Mainz, and so on, …

Measurement Of Unpolarized And Polarized Cross Sections For Deeply Virtual Compton Scattering On The Proton At Jefferson Laboratory With Clas, N. Saylor, B. Hirlinger, B. Guegan, V. D. Burkert, L. Elouadrhiri, M. Garcon, F. X. Girod, M. Guidal, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

This paper reports the measurement of polarized and unpolarized cross sections for the ep→e′p′γ reaction, which is composed of deeply virtual Compton scattering (DVCS) and Bethe-Heitler (BH) processes, at an electron beam energy of 5.88 GeV at the Thomas Jefferson National Accelerator Facility using the Large Acceptance Spectrometer CLAS. The unpolarized cross sections and polarized cross section differences have been measured over broad kinematics, 0.10 < x_B < 0.58, 1.0 < Q² <4.8 GeV² and 0.09<−t <2.00 GeV². The results are found to be consistent with previous CLAS data, and these new data are discussed in the framework of the generalized parton distribution approach. Calculations …

Beryllium And Indium Activation Measurements Of Total Neutron Yield From A Pulsed Photoneutron Source, Kristina K. Brown

Physics & Astronomy ETDs

A pulsed photoneutron source consisting of a beryllium sphere and a 5 MeV endpoint 30 ns bremsstrahlung beam emanating from the Mercury pulsed-power source was assembled and tested in October 2017 at the Naval Research Laboratory (NRL) in Washington, D.C. [1]. The objective of this experiment was to verify the feasibility of using a pulsed power source to create a large number of photoneutrons in a short period of time, leveraging the low photoneutron production threshold of 9Be to maximize neutron production. Several diagnostics were deployed to characterize the source and target, including indium and beryllium activation detectors that measured …

Measurements Of The Gamma(Upsilon)P -> P ’Pi(+)Pi(- )Cross Section With The Clas Detector For 0.4 Gev2 < Q(2) < 1.0 Gev2 And 1.3 Gev < W < 1.825 Gev, G. Fedotov, Iu A. Skorodumina, V. D. Burkert, R. W. Gothe, K. Hicks, V. Mokeev, S. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

New results on the single-differential and fully integrated cross sections for the process γ_vp -> p'π⁺π^- are presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the kinematic region of the reaction invariant mass W from 1.3 to 1.825 GeV and the photon virtuality Q² from 0.4 to 1.0 GeV². The cross sections were obtained in narrow Q² bins (0.05 GeV²) with the smallest statistical uncertainties achieved in double-pion electroproduction experiments to date. The results were found to be in …

Exclusive Photoproduction Of Pi Degrees Up To Large Values Of Mandelstam Variables S, T, And U With Clas, M. C. Kunkel, M. J. Amaryan, I. I. Strakovsky, J. Ritman, G. R. Goldstein, K. P. Adhikari, S. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

Exclusive photoproduction cross sections have been measured for the process γp -> pπ⁰ [e⁺ e^- (γ)] with the Dalitz decay final state using tagged photon energies in the range of Eγ = 1.275 – 5.425 GeV. The complete angular distribution of the final state π⁰, for the entire photon energy range up to large values of t and u, has been measured for the first time. The data obtained show that the cross section dσ / dt, at mid to large angles, decreases with energy as s^{-6.89 +/- 0.26 …}

Semi-Inclusive Pi(0) Target And Beam-Target Asymmetries From 6 Gev Electron Scattering With Clas, S. Jawalkar, S. Koirala, H. Avakian, P. Bosted, K. A. Griffioen, C. Keith, S. E. Kuhn, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic ¹⁴NH₃ target, and extracted double and single target spin asymmetries for ep→e′ π⁰ X in multidimensional bins in four-momentum transfer (1.0 2 < 3.2 GeV²), Bjorken -x (0.12 < x < 0.48), hadron energy fraction (0.4 < z 0.7), tranverse pion meomentum (0 < PT < 1.0 GeV), and azimuthal angle ϕ_h between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x …

Heavy Flavour In Jets And Azimuthal Correlations, Patrick J. Steffanic

Physics

We studied heavy-flavor azimuthal correlations using the semi-leptonic decay channel of hard-scattered bottom quarks in proton-proton collisions at center-of-mass energies of 7 TeV. We used a mixed-event method to produce a corrected correlation that hinted at back-to-back pair production. We further studied the jets resulting from these heavy-flavor hard scatterings, and jets resulting from light-flavor and gluon scattering. We compared several kinematic variables from each of the jet populations, concluding that novel kinematic variables must be developed in order to effectively separate the jet populations.

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. M. Park, R. W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J. -M. Laget, K. P. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep→e′nπ+, above the resonance region at backward pion center-of-mass angles. The φπ⁎-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of three-quark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon. Keywords: TDA, Exclusive single pion, Eletroproduction, CLAS

Measurement Of The Beam Asymmetry Sigma And The Target Asymmetry T In The Photoproduction Of Omega Mesons Off The Proton Using Clas At Jefferson Laboratory, P. Roy, Z. Akbar, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, Gerard P. Gilfoyle

Physics Faculty Publications

The photoproduction of omega mesons off the proton has been studied in the reaction γp -> pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω -> π⁺π^-π⁰, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the …

Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

The f₀ (1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the f₀ (1500) via decay into the K-S(0) K-S(0) channel using the CLAS detector. The reaction γp -> f_Jp -> K-S(0) K-S(0) p, where J = 0,2, was measured with photon energies from 2.7-5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured …

Investigation Of Neutron Induced Ternary Fission With The Niffte Time Projection Chamber, Alex C. Kemnitz

Physics

Ternary fission is a rare occurrence in which three particles are produced from a single fission event. This analysis uses tracked fission event data recorded by NIFFTE’s time projection chamber with a series of refined cuts to isolate all possible ternary events. The experiment used two targets, each consisting of two isotopes; one target was Pu-239 and U-235, and the other was U-238 and U-235. The data was used to measure the ternary/binary fission ratios for each isotope. The ratios for the Pu-239 and U-235 target that were found are shown to be too high due to alpha contamination. The …

Studying The Reaction 34ar(Alpha,P)37k And Its Impact On Xrb Nucleosynthesis And Observables, Amber C. Lauer

LSU Doctoral Dissertations

Type I X-Ray bursts (XRB’s) are a site of nucleosynthesis for some proton-rich elements up to A=100. These stellar explosions occur on the surface of a neutron star in a Low- Mass X-ray Binary accreting H- and He-rich material. During accretion nuclear burning occurs through stable processes such as the hot CNO (HCNO) cycles, but at some critical accretion condition the the HCNO cycles are bypassed through a breakout reaction. This triggers the thermonuclear runaway of the XRB. During the burst, nucleosynthesis on certain proton-rich nuclei, called (α, p) waiting points, can stall which could stall the energy generation and …