Nuclear Commons^™

Determining The 17f(Α,P)20ne Reaction Rate For Application In Type I X-Ray Bursts, William Braverman

LSU Doctoral Dissertations

The ¹⁷F(α, p)²⁰Ne reaction has been identified as an alternate pathway for breakout from the hot-CNO cycle that can be important in some X-ray burst scenarios. The ¹⁷F(α, p)²⁰Ne reaction rate was previously determined through a parameterized exponential S-factor with a large enhancement from thermally-excited states based on statistical models with large uncertainties. We have measured the time-inverse ²⁰Ne(p,α)¹⁷F cross section at center-of-mass energies ranging from 5.50 to 7.10 MeV using an activation method with a proton beam on a neon gas cell. Coincident detections of 511-keV γ-rays, resulting from electron-positron …

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.

The Present And Future Of Qcd, P. Achenbach, D. Adhikari, A. Afanasev, F. Afzal, C. A. Aidala, A. Al-Bataineh, D. K. Almaalol, M. Amaryan, D. Androić, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, E. C. Aschenauer, H. Atac, H. Avakian, T. Averett, C. Ayerbe Gayoso, X. Bai, M. Zurek, Et. Al.

Physics Faculty Publications

This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming …

Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati

Physics Faculty Publications

We investigate the rf performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120–165 °C for an extended period of time (24–48 h) either in high vacuum or in a low partial pressure of ultrapure nitrogen. The improvement in 𝑄0 with a 𝑄 rise was observed when nitrogen gas was injected at ∼300 °C during the cavity cooldown from 800 °C and held at 165 °C, without any degradation in accelerating gradient over the baseline performance. The treatment was applied to several elliptical cavities with frequency ranging …

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 …

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 …

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.

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 …

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 …

Inverse Kinematics Proton Scattering Of P41, Benjamin R. Klybor

Physics and Astronomy Summer Fellows

We have measured the gamma-ray spectrum of P41 using proton scattering in inverse kinematics with the NSCL/Ursinus College liquid hydrogen target and the GRETINA gamma-ray tracking array. We present preliminary results, including gamma-ray intensities and branching ratios.

Test Of New Readout Electronics For The Bonus12 Experiment, Mathieu Ehrhart

Physics Theses & Dissertations

For decades, electron-proton scattering experiments have been providing a large amount of data on the proton structure function. However, because of the instability of free neutrons, fewer experiments have been able to study the neutron structure function. The BONuS collaboration at Jefferson Laboratory addresses this challenge by scattering electrons off a deuterium target, using a RTPC capable of detecting the low-momentum spectator protons near the target. Events of electrons scattering on almost free neutrons are selected by constraining the spectator protons to very low momenta and very backward scattering angles. In 2005, BONuS successfully measured the neutron structure with scattering …

The Chiral Magnetic Effect In Heavy Ion Collisions From Hydrodynamic Simulations, Elias Lilleskov

Macalester Journal of Physics and Astronomy

The quark-gluon plasma created in heavy ion collisions is an exotic state of matter in which many unusual phenomena are manifested. One such phenomenon is the "Chiral-Magnetic Effect" (CME), wherein the powerful magnetic fields generated by colliding ions spin-polarize chiral quarks, causing a net transport effect in the direction of the fields. The CME predicts specific charge-dependent correlation observables, for which experimental evidence was reported, although the evidence is subject to background contamination. Isobaric collision experiments have been planned for 2018 at RHIC, which will study this effect by comparing 96Ru-96Ru and 96Zr-96Zr collisions. The two colliding systems are expected …

Radiation Therapy Medical Physics Review – Delivery, Interactions, Safety, Feasibility, And Head To Head Comparisons Of The Leading Radiation Therapy Techniques, Cielle Collins

Honors Theses and Capstones

Radiation therapy uses high energy radiation to kill cancer cells. Radiation therapy for cancer treatment can take the form of photon therapy (using x-rays and gamma rays), or charged particle therapy including proton therapy and electron therapy. Within these categories, numerous methods of delivery have been developed. For example, a certain type of radiation can be administered by a machine outside of the body, called external-beam radiation therapy, or by a “seed” placed inside of the body near cancer cells, called internal radiation therapy or brachytherapy. Approximately half of all cancer patients receive radiation therapy, and the form of radiation …

The Utility Of Table-Top Exercises In Teaching Nuclear Security, Christopher Hobbs, Luca Lentini, Matthew Moran

International Journal of Nuclear Security

In the emerging field of nuclear security, those responsible for education and training are constantly seeking to identify and engage with tools and approaches that provide for a constructive learning environment. In this context, this paper explores the nature and value of Tabletop exercises (TTX) and how they can be applied in the nuclear security context. On the one hand, the paper dissects the key components of the TTX and considers the broader pedagogical benefits of this teaching method. On the other hand, the paper draws lessons from the authors’ experience of running TTXs as part of nuclear security professional …

The Rise Of Nuclear Energy In Arab States: Future Impacts, Brittany Broder

Mahurin Honors College Capstone Experience/Thesis Projects

The signing of the Iranian nuclear deal during the Summer of 2015 highlighted the threat of nuclear proliferation from foreign powers, but largely overlooked the rise of nuclear energy in the Middle East and North Africa (MENA). With growing energy demands and heightened environmental regulations, countries in this region are turning to nuclear power to fuel their next generation. However, the rise of nuclear power in the MENA region holds serious implications for the future of the area’s energy, economic, and social reforms that have largely gone unexplored as a whole thus far. The purpose of this thesis is to …

Consequence Management: Evaluating And Developing International Responses To Nuclear And Radiological Disasters, Timothy Taylor

Dissertations and Theses

No abstract provided.

Investigation Of Time Varying Nuclear Decay Rates, Peter G. Barton, Rafael F. Lang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Since the discovery of radioactive decay, radioactive decay rates have consistently shown to be constant. Recently, groups of researchers around the world have noticed variation in the decay rates of different radioactive isotopes, while other groups have noticed no such effect. If the variation is truly varying decay rates, this would imply groundbreaking new physics and would have implications for practices such as carbon dating. More sophisticated experiments are required to determine if the variations are truly new physics or systematic effects inherent to nuclear decay experiments. We are building an experiment where activity data from various radioactive sources will …

Superfluidity In Neutron Stars, Samuel J. Witte

Undergraduate Theses—Unrestricted

Nucleon pairing is studied with specific considerations directed toward the possible influence on neutron star cooling. We present an in-depth analysis of BCS theory using realistic nuclear potentials and consider the impact short-range correlations can have on the gap. Gap calculations are incorporated into neutron star cooling simulations and the significance of the 3P2 −3F2 channel in various hadronic cooling models is closely examined. An analysis of the 1S0 gap in neutron matter suggests short-range correlations can drastically alter the magnitude, density range, and temperature dependence of the gap. While the newly constructed 1S0 gap does not significantly alter the …

Tof-Sims For Rapid Nuclear Forensics Evaluation Of Uranium Oxide Particles, Hannah E. Hocking

Theses and Dissertations

Because of nuclear proliferation concerns, nuclear material must be safeguarded, and peaceful intentions verified. The field of nuclear forensics addresses these concerns. While established nuclear forensic techniques exist, quicker, more accurate and less expensive methods are of interest for nonproliferation applications. Currently a host of different analytical techniques, requiring a week or longer, are employed to obtain isotopic ratios, chemical abundances and morphology for forensic particulate samples. Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is a candidate technology for rapid evaluation of these properties for small amounts of nuclear materials. After a thorough investigation, this study found TOF-SIMS to be particularly …

Directional Pair-Production Spectrometer Design For Airborne Stand-Off Detection Of Special Nuclear Material, William L. Harrell

Theses and Dissertations

The purposes of this research are to experimentally and theoretically prove the concept of a directional pair-production spectrometer to detect and locate the tailings that are created when making Special Nuclear Material (SNM) at stand-off distances from a remotely piloted vehicle (RPV). A directional pair-production spectrometer uses the information garnered from the high energy gamma rays emitted by these SNM manufacturing tailings to perform pair-production spectroscopy and identify the isotope of interest. Through simultaneous operation as a Compton camera, the detection system will be able to measure rudimentary directional information from the medium energy gamma decays. The detector used for …

Measurement Of The Electric Form Factor Of The Neutron At Q² = 0.5 And 1.0 Gev²/C², Jefferson Lab E93-026 Collaboration, G. Warren, F. Wesselmann, H. Zhu, A. Klimenko, S. E. Kuhn, L. Yuan, J. Yun, B. Zihlmann, Et Al.

Physics Faculty Publications

The electric form factor of the neutron was determined from measurements of the ^→d( ^→e, e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (¹⁵ND₃) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector. We find Gⁿ_E =0.0526 ± 0.0033(stat) ± 0.0026(sys) and 0.0454 ± 0.0054 ± 0.0037 at Q²=0.5 and 1.0 (GeV/c)², respectively.

Physical And Managed Risk Of Nuclear Waste, Lennart Sjöberg, Britt-Marie Drottz-Sjöberg

RISK: Health, Safety & Environment (1990-2002)

The authors describe their work on the perceived risk of nuclear waste in Sweden. Three levels of waste were studied, and comparisons between the perceptions of the public, politicians and nuclear experts are made.

Book Review Of Alla Yaroshinskaya, Chernobyl: The Forbidden Truth, John M. Gleason

RISK: Health, Safety & Environment (1990-2002)

Review of the book: Alla Yaroshinskaya, Chernobyl: The Forbidden Truth (Michele Kahn & Julia Sallabank, trans. University of Nebraska Press 1995). Introduction, foreword, list of illustrations, photographs. ISBN 0-8032-4912-8. [136 pp. Cloth $25.00; Paper $10.00. 312 N. 14th Street, Lincoln NE 68588-0484.]