Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Nuclear

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 1425

Full-Text Articles in Physics

Precision Measurement Of The Beam-Normal Single-Spin Asymmetry In Forward-Angle Elastic Electron-Proton Scattering, Qweak Collaboration, David Armstrong, Wouter Deconinck, K. Bartlett, J. C. Cornejo, R. D. Carlini, James F. Dowd, J. M. Finn, Valerie M. Gray, K. Grimm, J. R. Hoskins, J. P. Leckey, Jeong Han Lee, Joshua A. Magee, Victoria F. Owen Sep 2020

Precision Measurement Of The Beam-Normal Single-Spin Asymmetry In Forward-Angle Elastic Electron-Proton Scattering, Qweak Collaboration, David Armstrong, Wouter Deconinck, K. Bartlett, J. C. Cornejo, R. D. Carlini, James F. Dowd, J. M. Finn, Valerie M. Gray, K. Grimm, J. R. Hoskins, J. P. Leckey, Jeong Han Lee, Joshua A. Magee, Victoria F. Owen

Arts & Sciences Articles

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of theta_lab = 7.9 degrees and a mean energy of 1.149 GeV. The asymmetry result is B_n = -5.194 +- 0.067 (stat) +- 0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering ...


Eusectra: European Nuclear Security Training Centre Providing Hands-On Training And Education In Nuclear Security And Safeguards, Willem Janssens, Veronique Berthou, Abbas Kamel, Jean Galy, Klaus Luetzenkirchen, Klaus Mayer, Stefan Nonneman Jul 2020

Eusectra: European Nuclear Security Training Centre Providing Hands-On Training And Education In Nuclear Security And Safeguards, Willem Janssens, Veronique Berthou, Abbas Kamel, Jean Galy, Klaus Luetzenkirchen, Klaus Mayer, Stefan Nonneman

International Journal of Nuclear Security

The European Nuclear Security Training Centre (EUSECTRA) inaugurated under this global name about 10 years ago and operated by the European Commission Joint Research Centre (JRC), located both on the Karlsruhe (Germany) and Ispra (Italy) sites, includes a large variety of capacity building and professional development activities which span from the hands-on training for nuclear security and safeguards actors (e.g. respectively border guards or customs and nuclear inspectors) to educational efforts in both nuclear security and safeguards. Whereas the first ones, which gave rise to the new name, focus mainly on detection, on-site assistance, crime-scene management, technical reach-back and ...


Physical Protection System, Corrective Actions, And Weaknesses Identification Based On Nuclear Security Series: The Hypothetical Atomic Research Institute (Hari) Case, Ouadie Kabach, Abdelouahed Chetaine, Abdelfettah Benchrif Jul 2020

Physical Protection System, Corrective Actions, And Weaknesses Identification Based On Nuclear Security Series: The Hypothetical Atomic Research Institute (Hari) Case, Ouadie Kabach, Abdelouahed Chetaine, Abdelfettah Benchrif

International Journal of Nuclear Security

The paper is an attempt, based on the IAEA’s Nuclear Security Series (NSS), to identify any unacceptable dysfunction of Physical Protection System (PPS) of the Material Test Reactor (MTR) facility in a Hypothetical Atomic Research Institute (HARI). The evaluation of an existing or a proposed PPS requires a methodical approach whereby the ability of the security system to meet defined protection goals as the safeguard against possibility of sabotage and theft should be measured. Without such kind of careful assessment, the PPS might waste valuable resources on unnecessary protection or, worse yet, fail to provide adequate protection at critical ...


Investigation Of Finite Temperature And Continuum Effects On Nuclear Excitations, Herlik Wibowo Jun 2020

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 ...


Small-X Qcd Calculations With A Biased Ensemble, Gary Kapilevich Jun 2020

Small-X Qcd Calculations With A Biased Ensemble, Gary Kapilevich

Dissertations, Theses, and Capstone Projects

In this dissertation, I will argue that we can study functional fluctuations in unintegrated gluon distributions, in the MV model as well as JIMWLK, using reweighting techniques, which will allow me to calculate QCD observables with "biased ensembles". This technique will enable me to study rare functional configurations of the gluon distributions, that might have been selected for in, for example, the centrality criteria used by the ATLAS and ALICE collaborations. After a review of these techniques, as well as a review of QCD physics at high energy in general, I will use biased ensembles to compute observables in two ...


Transport In Neutron Star Mergers, Steven Patrick Harris May 2020

Transport In Neutron Star Mergers, Steven Patrick Harris

Arts & Sciences Electronic Theses and Dissertations

Neutron star mergers are the only situation in nature in which we find matter compressed to several times nuclear saturation density and temperatures of several tens of MeV. By observing and numerically simulating neutron star mergers, we can learn about the nature of matter at high temperatures and densities. Neutron star merger simulations evolve Einstein's equations of general relativity coupled to the equations of relativistic hydrodynamics along with a nuclear equation of state, which describes the neutron star matter. Many simulations also take into account neutrino transport and electrodynamics. The purpose of this thesis is to see whether other ...


Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, Anya Wolterman May 2020

Calculating Centrality Variables And Geometric Quantities Associated With High Energy Pb+Pb And Au+Au Collisions Using A Monte Carlo Glauber Model, Anya Wolterman

Macalester Journal of Physics and Astronomy

The Glauber model provides insight into the initial state of nuclear collisions by treating them in terms of the interactions between their constituent nucleons, in accordance with theories about the scattering of composite particles. These phenomenological techniques are commonly used to determine various geometric quantities associated with such complex, femtoscopic many-body systems. The Monte Carlo Glauber approach uses a random impact parameter and measured nuclear densities to investigate quantifiable properties like particle multiplicity and average geometric eccentricity for heavy ion collisions. The former involves incorporating a particle production model to plot the total transverse energy or the number of particles ...


Studies In Seop Hyperpolarized 3he: Measuring Ko And The Spatial Dependence Of Alkali Polarization, Michael Cairo May 2020

Studies In Seop Hyperpolarized 3he: Measuring Ko And The Spatial Dependence Of Alkali Polarization, Michael Cairo

Undergraduate Honors Theses

3He is an isotope of helium whose nucleus is composed of two protons and one neutron. The proportion of atoms whose spins are pointed along the same direction in a volume of 3He gas is known as the polarization. This study entails two experiments in the field of 3He polarimetry concerned with measuring the polarization of a 3He cell and reducing the uncertainty associated with it. 3He cells are full of gaseous 3He, along with alkali metal vapors, K and Rb in our case. The polarization of a 3He cell can be measured ...


Measurements Of Fast Alpha Decays In The 100sn Region, Ian Connor Cox May 2020

Measurements Of Fast Alpha Decays In The 100sn Region, Ian Connor Cox

Chancellor’s Honors Program Projects

No abstract provided.


396— Radioactive Decay Calibrations Of Rics Using 41 Ar, Emily Vanderbilt, Nicole Gindling Apr 2020

396— Radioactive Decay Calibrations Of Rics Using 41 Ar, Emily Vanderbilt, Nicole Gindling

GREAT Day

The short-lived isotope-counting system (SLIC) being built for the OMEGA laser facility at LLE requires gaseous radioisotopes for calibration purposes. Using a Plutonium-Beryllium (Pu-Be) source at SUNY Geneseo, 41Ar was made by capturing thermal neutrons via the 40Ar(n,gamma) reaction. Once activated, 41Ar beta decays, producing an electron with endpoint energy of 1.198 MeV. The daughter product is found to be the second excited state of 41K 99.1% of the time. This decays to the ground state and emits a 1.293 MeV gamma ray. To accurately measure the beta activity of 41Ar, the Gamma-X system at ...


293— Moly - Monitoring Oxygen Levels In Ntof Scintillators Using Cosmic Ray Muons, Sean King, Matthew Signor Apr 2020

293— Moly - Monitoring Oxygen Levels In Ntof Scintillators Using Cosmic Ray Muons, Sean King, Matthew Signor

GREAT Day

High Energy Density Physics and Inertial Confinement Fusion facilities employ nTOF methods to measure neutron energies. Laser induced fusion facilities use the beam pulse as a start signal and Xylene scintillators as the stop signal to obtain the time of flight. To improve timing performance, the scintillator liquid is quenched with oxygen reducing the light production. However, oxygen reacts with the scintillator liquid causing the detector photo flash decay time to increase that reduces the energy resolution of the detector. An in-situ monitoring system which uses cosmic ray muons to determine the oxygen concentration, is being developed at SUNY Geneseo ...


Heavy Quark Expansion For Heavy-Light Light-Cone Operators, Shuai Zhao Apr 2020

Heavy Quark Expansion For Heavy-Light Light-Cone Operators, Shuai Zhao

Physics Faculty Publications

We generalize the celebrated heavy quark expansion to nonlocal QCD operators. By taking nonlocal heavy-light current on the light-cone as an example, we confirm that the collinear singularities are common between QCD operator and the corresponding operator in heavy quark effective theory (HQET), at the leading power of 1/M expansion. Based on a perturbative calculation in operator form at one-loop level, a factorization formula linking QCD and HQET operators is investigated and the matching coefficient is determined. The matching between QCD and HQET light-cone distribution amplitudes (LCDAs) as well as other momentum distributions of hadron can be derived as ...


Development Of Convolutional Neural Nets For Κ/Π Differentiation At The Gluex Experiment, Matthew Mceneaney Apr 2020

Development Of Convolutional Neural Nets For Κ/Π Differentiation At The Gluex Experiment, Matthew Mceneaney

Undergraduate Honors Theses

Lattice Quantum Chromodynamics (QCD) calculations predict a whole spectrum of exotic hybrid mesons thought to arise from gluonic excitation between a quark and antiquark. A systematic survey of strange and non-strange decay modes would be necessary to confirm this, and in particular studying decays to kaonic final states could confirm initial lattice QCD predictions. The GlueX experiment at Jefferson Lab studies the non-perturbative regime of the strong interaction and searches for hybrid mesons through light-quark meson spectroscopy; thus, kaon identification is critical for the GlueX experiment. Currently, the GlueX DIRC (Detection of Internally Reflected Cherenkov light) detectors provide clear kaon ...


Data Acquisition And Analysis For Helicity-Correlated Asymmetries In Prex-Ii, Quinn Campagna Apr 2020

Data Acquisition And Analysis For Helicity-Correlated Asymmetries In Prex-Ii, Quinn Campagna

Undergraduate Honors Theses

The goal of PREx-II is to measure the radius of the neutron distribution in the nucleus of 208Pb to a precision of +/-1%, the original proposed goal of PREx-I. This is done by scattering polarized electrons off of a lead target, taking advantage of the parity-violating nature of the weak interaction. The difference in the scattering cross section for each helicity state allows us to extract the neutron radius of the nucleus. There can, however, be helicity-correlated beam asymmetries that are not related to the weak interaction. In order to extract these errors, we periodically modulate the beam energy ...


Author Correction: Closing The Nuclear Fuel Cycle With A Simplified Minor Actinide Lanthanide Separation Process (Alsep) And Additive Manufacturing, Artem V. Gelis, Peter Kozak, Andrew T. Breshears, M. Alex Brown, Cari Launiere, Emily L. Campbell, Gabriel B. Hall, Tatiana G. Levitskaia, Vanessa E. Holfeltz, Gregg J. Lumetta Jan 2020

Author Correction: Closing The Nuclear Fuel Cycle With A Simplified Minor Actinide Lanthanide Separation Process (Alsep) And Additive Manufacturing, Artem V. Gelis, Peter Kozak, Andrew T. Breshears, M. Alex Brown, Cari Launiere, Emily L. Campbell, Gabriel B. Hall, Tatiana G. Levitskaia, Vanessa E. Holfeltz, Gregg J. Lumetta

Chemistry and Biochemistry Faculty Publications

No abstract provided.


Stellar Nucleosynthesis: Direct Measurement Of The Neutron-Capture Cross Sections Of Stable Germanium Isotopes And Design Of A Next Generation Ion Trap For The Study Of Beta-Delayed Neutron Emission, Alexander Laminack Jan 2020

Stellar Nucleosynthesis: Direct Measurement Of The Neutron-Capture Cross Sections Of Stable Germanium Isotopes And Design Of A Next Generation Ion Trap For The Study Of Beta-Delayed Neutron Emission, Alexander Laminack

LSU Doctoral Dissertations

Knowledge of stellar nuclear reaction rates is critical to understanding the cosmic origins of the abundances of elements. In order to determine these reaction rates, accurate measurements of nuclear cross sections are needed. This thesis presents the results of an experiment to directly measure the neutron capture cross sections of 70-Ge, 72-Ge, 74-Ge, and 76-Ge. These measurements were performed at the Los Alamos Neutron Science CEnter (LANSCE) using the Detector for Advanced Neutron Capture Experiments (DANCE). This is the first direct measurement for many of these isotopes across the neutron energy spectrum of 10 eV to 1 MeV using the ...


Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, Hongyong Zhang Jan 2020

Effects Of Energy Resolution And Bin Size On The Measurements Of Nuclear Neutron Distributions Using Coherent Elastic Neutrino-Nucleus Scattering, Hongyong Zhang

Honors Theses

Coherent elastic neutrino-nucleus scattering is a process that involves the neutral-current scattering of a neutrino with an entire nucleus, which probes more bulk properties of the nucleus. Using the Taylor expansion of the form factors and calculation of effective moments that sums over isotopes, we successfully simulate the events for coherent elastic neutrino-nucleus scattering for detectors using Ar and Ge and demonstrate that coherent elastic neutrino-nucleus scattering can determine both the second moment and the fourth moment. Running the Monte Carlo simulation using a detector filled with 10 tonnes of natural germanium, a neutrino flux of 3*10^7 neutrinos ...


Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen Jan 2020

Neutron Valence Structure From Nuclear Deep Inelastic Scattering, E. P. Segarra, A. Schmidt, T. Kutz, D. W. Higinbotham, E. Piasetzky, M. Strikman, L. B. Weinstein, O. Hen

Physics Faculty Publications

Mechanisms of spin-flavor SU(6) symmetry breaking in quantum chromodynamics (QCD) are studied via an extraction of the free neutron structure function from a global analysis of deep inelastic scattering (DIS) data on the proton and on nuclei from A = 2 (deuterium) to 208 (lead). Modification of the structure function of nucleons bound in atomic nuclei (known as the EMC effect) are consistently accounted for within the framework of a universal modification of nucleons in short-range correlated (SRC) pairs. Our extracted neutron-to-proton structure function ratio Fn2/Fp2 becomes constant for xB ≥ 0.6, equaling 0 ...


Probing Few-Body Nuclear Dynamics Via ³H And ³He (E E'P) Pn Cross-Section Measurements, R. Cruz-Torres, F. Hauenstein, D. Bulumulla, C. Hyde, M. Khachatryan, M.N.H. Rashad, L.B. Weinstein, Et. Al., Jefferson Lab Hall A. Tritium Collaboration Jan 2020

Probing Few-Body Nuclear Dynamics Via ³H And ³He (E E'P) Pn Cross-Section Measurements, R. Cruz-Torres, F. Hauenstein, D. Bulumulla, C. Hyde, M. Khachatryan, M.N.H. Rashad, L.B. Weinstein, Et. Al., Jefferson Lab Hall A. Tritium Collaboration

Physics Faculty Publications

We report the first measurement of the (e, e'p) three-body breakup reaction cross sections in helium-3 (3He) and tritium (3H) at large momentum transfer [< Q2> ≈ 1.9 (GeV/c)2] and xB> 1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40 ≤ pmiss ≤ 500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ± 20%, is observed between data and ...


Verification Of The Vertical Bubble Flow Experiments, Reginald Jones Ii Jan 2020

Verification Of The Vertical Bubble Flow Experiments, Reginald Jones Ii

Theses and Dissertations

Detailed experimental design to support basic pedagogy of flow regimes – single phase liquid, bubbly, slug, annular, dispersed droplet, and single phase vapor – occurring in flow channels of nuclear reactors has been developed for EGMN 203 - Nuclear Engineering Practicum offering at Virginia Commonwealth University’s Department of Mechanical and Nuclear Engineering. The laboratory instruction will be used to help students forming ideas and understanding flow regimes occurring in nuclear engineering applications. We designed and constructed four water columns to act as surrogates for water channels in a nuclear reactor. Each column was used for a different experiment: salted versus unsalted water ...


Decreasing Uncertainty In Nuclear Magnetic Resonance Measurements Through The Application Of Pappus Chains, Ryan Williams Jan 2020

Decreasing Uncertainty In Nuclear Magnetic Resonance Measurements Through The Application Of Pappus Chains, Ryan Williams

Honors Theses and Capstones

To make further advancements in nuclear polarization, the Dynamic Nuclear Polarization Group at the University of New Hampshire requires an accurate measurement of the polarization of their materials. Through a non-traditional method of data analysis, the uncertainty in this polarization measurement via Nuclear Magnetic Resonance (NMR) was reduced. To extract the polarization, we measure an NMR signal through the real impedance of our circuitry, whose area is proportional to the polarization. However, our signal size depends on how in-tune our circuitry is with a specific frequency, with the signal growing smaller the less in-tune it becomes. A new method of ...


Remark On Lehnert’S Revised Quantum Electrodynamics (Rqed) As An Alternative To Francesco Celani’S Et Al. Maxwell-Clifford Equations: With An Outline Of Chiral Cosmology Model And Its Role To Cmns, Florentin Smarandache, Victor Christianto, Yunita Umniyati Jan 2020

Remark On Lehnert’S Revised Quantum Electrodynamics (Rqed) As An Alternative To Francesco Celani’S Et Al. Maxwell-Clifford Equations: With An Outline Of Chiral Cosmology Model And Its Role To Cmns, Florentin Smarandache, Victor Christianto, Yunita Umniyati

Mathematics and Statistics Faculty and Staff Publications

In a recent paper published in JCMNS in 2017, Francesco Celani, Di Tommaso & Vassalo argued that Maxwell equations rewritten in Clifford algebra are sufficient to describe the electron and also ultra-dense deuterium reaction process proposed by Homlid et al. Apparently, Celani et al. believed that their Maxwell-Clifford equations are an excellent candidate to surpass both Classical Electromagnetic and Zitterbewegung QM. Meanwhile, in a series of papers, Bo Lehnert proposed a novel and revised version of Quantum Electrodynamics (RQED) based on Proca equations. Therefore, in this paper, we gave an outline of Lehnert’s RQED, as an alternative framework to Celani ...


Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory, Mark Broering Jan 2020

Study Of Cell Charging Effects For The Neutron Electric Dipole Moment Experiment At Oak Ridge National Laboratory, Mark Broering

Theses and Dissertations--Physics and Astronomy

The neutron electric dipole moment (nEDM) collaboration at the Spallation Neutron Source plans to use ultra-cold neutrons in superfluid helium to improve the nEDM limit by about two orders of magnitude. In this apparatus, neutrons are stored in poly(methyl methacrylate), PMMA, cells located in a strong, stable electric field. This electric field is produced by high voltage electrodes located outside of the neutron cells. Several sources generate charged particles inside the neutron cells. The electric field pulls these charges farther apart, attracting each to the oppositely charged electrode. As the charges build up on the cells walls, they create ...


Evaluation Of The Activity Of Zn-65 Isotope And Radiation Dose Delivered To Drosophila Melanogaster, Wasiu Ajani Erinoso Jan 2020

Evaluation Of The Activity Of Zn-65 Isotope And Radiation Dose Delivered To Drosophila Melanogaster, Wasiu Ajani Erinoso

All Graduate Theses, Dissertations, and Other Capstone Projects

Radioactivity is a natural part of our environment. Ionizing radiation from radioactive materials can affect the life cycle of organisms; sometimes increase the rate of transition between cycle leading to the proliferation of cells as seen in some cancer cells or delay the rate of transition between cell cycle. A NaI detector is essential to determine the activity of a radioactive material. To determine the resolution of NaI detector and the efficiency of the geometry used for this experiment, quality control was done for NaI detector using 22Na reference source. The efficiency of the detector was used to verify the ...


Investigation Of Isomer Ratios In The Reactions (Γ, N) And (N, 2N) On Nuclei 76Ge And 82Se, Satimbay Palvanov, Turgunali Akhmadzhanov Dec 2019

Investigation Of Isomer Ratios In The Reactions (Γ, N) And (N, 2N) On Nuclei 76Ge And 82Se, Satimbay Palvanov, Turgunali Akhmadzhanov

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

The method of the induced activity measured the isomeric yield ratios and cross-sections ratios of reactions (γ, n) and (n, 2n) on nuclei 76Ge and 82Se. Samples of natural have been irradiated in the bremsstrahlung beam of the betatron SB-50 of National University of Uzbekistan in the energy range of 10-35 MeV with energy step of 1 MeV. For 14 MeV neutron irradiation, we used the NG-150 neutron generator of Institute of Nuclear Physics. The gamma spectra reactions products were measured with a spectroscopic system consisting of HPGe detector CANBERRA with energy resolution of 1.8 keV ...


Parton Distribution Functions From Loffe Time Pseudo-Distributions, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David Richards, Savvas Zafeiropoulos Dec 2019

Parton Distribution Functions From Loffe Time Pseudo-Distributions, Bálint Joó, Joseph Karpie, Kostas Orginos, Anatoly V. Radyushkin, David Richards, Savvas Zafeiropoulos

Physics Faculty Publications

In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two volumes, with lattice spacings a = 0.127 fm and a = 0.094 fm, for a pion mass of roughly 400 MeV. With two lattice spacings and two volumes, both continuum limit and infinite volume extrapolation systematic errors of the PDF are considered. In addition to the x dependence of the PDF, we compute their first two moments and compare them with the pertinent phenomenological determinations.


Generalized Parton Distributions And Pseudodistributions, Anatoly V. Radyushkin Dec 2019

Generalized Parton Distributions And Pseudodistributions, Anatoly V. Radyushkin

Physics Faculty Publications

We derive one-loop matching relations for the Ioffe-time distributions (ITDs) related to the pion distribution amplitude (DA) and generalized parton distributions (GPDs). They are obtained from a universal expression for the one-loop correction in an operator form, and will be used in the ongoing lattice calculations of the pion DA and GPDs within the parton pseudodistributions approach.


Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, S. Adhikari, A. Ali, M. J. Amaryan, A. Austregesilo, F. Barbosa, J. Barlow, A. Barnes, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, N. Wickramaarachchi, B. Zihlmann, The Gluex Collaboration Dec 2019

Beam Asymmetry Σ For The Photoproduction Of Η And Ή Mesons At Eγ = 8.8gev, S. Adhikari, A. Ali, M. J. Amaryan, A. Austregesilo, F. Barbosa, J. Barlow, A. Barnes, E. Barriga, R. Barsotti, T. D. Beattie, V. V. Berdnikov, T. Black, N. Wickramaarachchi, B. Zihlmann, The Gluex Collaboration

Physics Faculty Publications

We report on the measurement of the beam asymmetry Σ for the reactions →γp→pη and →γp→pη′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer −t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η′ in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Ση to Ση ...


Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework, Alison Constance Dreyfuss Nov 2019

Alpha Capture Reaction Rates For Nucleosynthesis Within An Ab Initio Framework, Alison Constance Dreyfuss

LSU Doctoral Dissertations

Clustering in nuclear systems has broad impacts on all phases of stellar burning, and plays a significant role in our understanding of nucleosynthesis, or how and where nuclei are produced in the universe. The role of alpha particles in particular is extremely important for nuclear astrophysics: 4He was one of the earliest elements produced in the Big Bang, it is one of the most abundant elements in the universe, and helium burning -- in particular, the triple-alpha process -- is one of the most important ``engines'' in stars. To better understand nucleosynthesis and stellar burning, then, it is important to develop ...


Weaponizing Radioactive Medical Waste - The Looming Threat, Shreekumar Menon, Vagish Kumar L.S. Nov 2019

Weaponizing Radioactive Medical Waste - The Looming Threat, Shreekumar Menon, Vagish Kumar L.S.

International Journal of Nuclear Security

Across the globe, use of radioactive substances for medical treatment, by hospitals has resulted in generation of toxic wastes on a large scale. Disposal of these wastes are being entrusted to waste disposal vendors. Environmental concerns, pressures, restrictions and high labor costs, compel these vendors to dump these wastes in third world countries, where enforcement and awareness are substantially low. Unrestricted access to these waste dumps is an open invitation to terror organizations to extract toxic substances and fabricate crude dirty bombs to threaten public safety, and cause low-level contamination of sensitive installations. It is therefore imperative to create an ...