Separated Response Function Ratios In Exclusive, Forward Π± Electroproduction,
2014
Old Dominion University
Separated Response Function Ratios In Exclusive, Forward Π± Electroproduction, G. M. Huber, H. P. Blok, C. Butuceanu, D. Gaskell, T. Horn, D. J. Mack, D. Abbott, A. Klein, L. M. Qin, K. Vansyoc
Physics Faculty Publications
The study of exclusive π± electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio R-L=sigma(pi-)(L) / sigma(pi+)(L) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of R-T=sigma(pi-)(L) / sigma(pi+)(L) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier …
Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime,
2014
Old Dominion University
Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft
Physics Faculty Publications
We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation …
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au + Au Collisions At Rhic,
2014
Old Dominion University
Beam-Energy Dependence Of Charge Separation Along The Magnetic Field In Au + Au Collisions At Rhic, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, C. D. Anson, A. Aparin, D. Arkhipkin, E. C. Aschenauer, G. S. Averichev, A. Banerjee, D. R. Beavis, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, H. Bichsel, M. Zyzak, Et Al., Star Collaboration
Physics Faculty Publications
Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with …
Radiogenic Second Cancer Risk Differences In Female Hodgkin Lymphoma Patients Treated With Proton Versus Photon Radiotherapies,
2013
The University of Texas Graduate School of Biomedical Sciences at Houston
Radiogenic Second Cancer Risk Differences In Female Hodgkin Lymphoma Patients Treated With Proton Versus Photon Radiotherapies, Kenneth L. Homann
Dissertations and Theses (Open Access)
Hodgkin Lymphoma (HL) is the most common cancer diagnosis of young adults in the United States. Advances in curative treatments for HL, including the use of photon radiation therapy (RT) techniques, have increased 10 year survival rates to approximately 90% among young patients. These RT treatments, however, contribute to an increased incidence of radiogenic second cancer (RSC) formation to the healthy tissue surrounding the tumor volume relative to the general population. These RSCs are the leading cause of death among long-term HL survivors. Proton therapy has been shown to reduce the therapeutic dose, and therefore, the risk of developing a …
Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor,
2013
University of Nevada, Las Vegas
Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor, Jeremiah Boles
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purpose of this study is to analyze the theoretical criticality of a spherical uranium-hexafluoride reactor with a transient, pulsed shockwave emanating from the center of the sphere in an outward-radial direction. This novel nuclear reactor design, based upon pulsed fission in a spherical enclosure is proposed for possible use in direct energy conversion, where the energy from fission products is captured through the use of electrostatic fields or through induction. An analysis of the dynamic behavior of the shockwave in this reactor is the subject of this thesis. As a shockwave travels through a fluid medium, the characteristics of …
Investigation Of Time Varying Nuclear Decay Rates,
2013
Purdue University
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 …
Measurement Of The Spin Structure Function Gd1 Of The Deuteron And Its Moments At Low Q2,
2013
Old Dominion University
Measurement Of The Spin Structure Function Gd1 Of The Deuteron And Its Moments At Low Q2, Krishna P. Adhikari
Physics Theses & Dissertations
Double polarization cross section differences (Δσ ||) for proton and deuteron targets have been measured in the EG4 experiment using the CLAS detector at Jefferson Lab. Longitudinally polarized electron beams at relatively low energies of 1.056, 1.337, 1.989, 2.256 and 3.0 GeV from the CEBAF accelerator were scattered off longitudinally polarized NH3 and ND3 targets. Scattered electrons were recorded at very low scattering angles (down to θ= 6°) with the help of a new dedicated Cherenkov counter and a special magnetic field setting of the CLAS detector in order to measure the cross section differences in the …
Remnants Of Spherical Shell Structures In Deformed Nuclei: The Impact Of An N = 64 Neutron Subshell Closure On The Structure Of N ≈ 90 Gadolinium Nuclei,
2013
University of Richmond
Remnants Of Spherical Shell Structures In Deformed Nuclei: The Impact Of An N = 64 Neutron Subshell Closure On The Structure Of N ≈ 90 Gadolinium Nuclei, T. J. Ross, R. O. Hughes, C. W. Beausang, J. M. Allmond, C. Angell, M. S. Basunia, D. L. Bleuel, J. T. Burke, R. J. Casperson, J. Escher, P. Fallon, R. Hatarik, J. Munson, S. Paschalis, M. Petri, L. Phair, J. J. Ressler, N. D. Scielzo
Physics Faculty Publications
Odd-mass gadolinium isotopes around N = 90 were populated by the (p,d) reaction, utilizing 25-MeV protons, resulting in population of low-spin quasineutron states at energies near and below the Fermi surface. Systematics of the single quasineutron levels populated are presented. A large excitation energy gap is observed between levels originating from the 2d3/2, 1h11/2, and 3s1/2 spherical parents (above the N = 64 gap), and the 2d5/2 (below the gap), indicating that the spherical shell model level spacing is maintained at least to moderate deformations.
First Observation Of 15be,
2013
Michigan State University
First Observation Of 15be, J. Snyder, T. Baumann, G. Christian, R. A. Haring-Kaye, P. A. Deyoung, Z. Kohley, B. Luther, M. Mosby, S. Mosby, A. Simon, J. K. Smith, A. Spyrou, Sharon L. Stephenson, M. Thoennessen
Physics and Astronomy Faculty Publications
The neutron-unbound nucleus 15Be was observed for the first time. It was populated using neutron transfer from a deuterated polyethylene target with a 59 MeV/u 14Be beam. Neutrons were measured in coincidence with outgoing 14Be particles and the reconstructed decay energy spectrum exhibits a resonance at 1.8(1) MeV. This corresponds to 15Be being unbound by 0.45 MeV more then 16Be thus significantly hindering the sequential two-neutron decay of 16Be to 14Be through this state.
Freeze-Out Dynamics Via Charged Kaon Femtoscopy In √ S N N = 200 Gev Central Au + Au Collisions,
2013
Old Dominion University
Freeze-Out Dynamics Via Charged Kaon Femtoscopy In √ S N N = 200 Gev Central Au + Au Collisions, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, S. Bültmann, I. Koralt, D. Plyku, Star Collaboration
Physics Faculty Publications
We present measurements of three-dimensional correlation functions of like-sign, low-transverse-momentum kaon pairs from √sNN=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event-generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass mT over the interval of 0.55≤mT …
Investigation Of Storage-Phosphor Autoradiography For The Rapid Quantitative Screening Of Air Filters For Emergency Response Purposes,
2013
University of Nevada, Las Vegas
Investigation Of Storage-Phosphor Autoradiography For The Rapid Quantitative Screening Of Air Filters For Emergency Response Purposes, Athena Marie Gallardo
UNLV Theses, Dissertations, Professional Papers, and Capstones
Past nuclear accidents, such as Chernobyl, resulted in a large release of radionuclides into the atmosphere. Radiological assessment of the vicinity of the site of the incident is vital to assess the exposure levels and dose received by the population and workers. Therefore, it is critical to thoroughly understand the situation and risks associated with a particular event in a timely manner in order to properly manage the event. Current atmospheric radiological assessments of alpha emitting radioisotopes include acquiring large quantities of air samples, chemical separation of radionuclides, sample mounting, counting through alpha spectrometry, and analysis of the data. The …
Contributions To The Cuore Collaboration,
2013
California Polytechnic State University - San Luis Obispo
Contributions To The Cuore Collaboration, Samuel Joseph Meijer
Physics
This paper describes work done between 2010 and 2013 to contribute to the CUORE collaboration, a physics collaboration searching for neutrinoless double-beta decay in tellurium. Measurement of this decay would indicate fundamental information about the nature of the neutrino. The implementation of a parylene-coated detector frame is described. Also, a temperature stabilization system for an automated gluing system was constructed. An image recognition algorithm is described for locating spots of glue and evaluating their acceptability.
Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev,
2013
Old Dominion University
Third Harmonic Flow Of Charged Particles In Au + Au Collisions At √ S Nn = 200 Gev, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, Av. V. Alakhverdyants, I. Alekseev, S. Bültmann, I. Koraly, Star Collaboration
Physics Faculty Publications
We report measurements of the third harmonic coefficient of the azimuthal anisotropy, v3, known as triangular flow. The analysis is for charged particles in Au+Au collisions at √sNN=200 GeV, based on data from the STAR experiment at the BNL Relativistic Heavy Ion Collider. Two-particle correlations as a function of their pseudorapidity separation are fit with narrow and wide Gaussians. Measurements of triangular flow are extracted from the wide Gaussian, from two-particle cumulants with a pseudorapidity gap, and also from event plane analysis methods with a large pseudorapidity gap between the particles and the event plane. These results are …
Quadrupole Collectivity In Neutron-Rich Fe And Cr Isotopes,
2013
University of Richmond
Quadrupole Collectivity In Neutron-Rich Fe And Cr Isotopes, H. L. Crawford, R. M. Clark, P. Fallon, A. O. Macchiavelli, T. Baugher, D. Bazin, C. W. Beausang, J. S. Berryman, D. L. Bleuel, C. M. Campbell, M. Cromaz, G. De Angelis, A. Gade, R. O. Hughes, I. Y. Lee, S. M. Lenzi, F. Nowacki, S. Paschalis, M. Petri, A. Poves, A. Ratkiewicz, T. J. Ross, E. Sahin, D. Weisshaar, K. Wimmer, R. Winkler
Physics Faculty Publications
Intermediate-energy Coulomb excitation measurements are performed on the N≥40 neutron-rich nuclei 66, 68Fe and 64Cr. The reduced transition matrix elements providing a direct measure of the quadrupole collectivity B(E2; 2+1→ 0+1) are determined for the first time in 68Fe42 and 64Cr40 and confirm a previous recoil distance method lifetime measurement in 66Fe40. The results are compared to state-of-the-art large-scale shell-model calculations within the full fpgd neutron orbital model space using the Lenzi-Nowacki-Poves-Sieja effective interaction and confirm the results of the calculations that show …
System-Size Dependence Of Transverse Momentum Correlations At √ S N N = 62.4 And 200 Gev At The Bnl Relativistic Heavy Ion Collider,
2013
Old Dominion University
System-Size Dependence Of Transverse Momentum Correlations At √ S N N = 62.4 And 200 Gev At The Bnl Relativistic Heavy Ion Collider, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, J. Alford, S. Bültmann, I. Koralt
Physics Faculty Publications
We present a study of the average transverse momentum (Pt) fluctuations and pt correlations for charged particles produced in Cu+Cu collisions at midrapidity for √sNN= 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the Pt correlation results have been studied as functions of the collision centralities, the ranges in Pt, the pseudorapidity η, and the azimuthal angle ϕ. The square root of the measured Pt correlations when scaled …
High-Spin Study Of The Shell Model Nucleus 88Y49,
2013
University of Richmond
High-Spin Study Of The Shell Model Nucleus 88Y49, M. Bunce, P. H. Regan, V. Werner, C. W. Beausang, A. Anagnostatou, M. Bowry, R. J. Casperson, D. Chen, N. Cooper, P. Goddard, R. O. Hughes, G. Ilie, P.J.R. Mason, B. Pauerstein, M. W. Reed, T. J. Ross, E. C. Simpson
Physics Faculty Publications
The near-yrast structure of the near-magic, odd-odd nucleus, 8839Y49, has been studied into the high-spin regime. Investigations were performed at the Wright Nuclear Structure Laboratory, Yale University, using the 74Ge(18O,p3n) and 76Ge(18O,p5n) fusion-evaporation reactions at beam energies of 60 and 90 MeV, respectively. Gamma-ray energy coincidence analyses using both double (γ2) and triple (γ3) fold coincidences, together with angular correlation measurements, have been used to extend the previously reported level scheme to an excitation energy of 8.6 MeV and a …
Near-Threshold Neutral Pion Electroproduction At High Momentum Transfers And Generalized Form Factors,
2013
University of Richmond
Near-Threshold Neutral Pion Electroproduction At High Momentum Transfers And Generalized Form Factors, P. Khetarpal, Gerard P. Gilfoyle, Et. Al.
Physics Faculty Publications
We report the measurement of near-threshold neutral pion electroproduction cross sections and the extraction of the associated structure functions on the proton in the kinematic range Q2 from 2 to 4.5 GeV2 and W from 1.08 to 1.16 GeV. These measurements allow us to access the dominant pion-nucleon s-wave multipoles E0+ and S0+ in the near-threshold region. In the light-cone sum-rule framework (LCSR), these multipoles are related to the generalized form factors G1π0p (Q2) and G2π0p (Q2). The data are compared to these …
Contributions To Background Reduction And Computer Simulations For Cuore & Cuore-0,
2013
California Polytechnic State University - San Luis Obispo
Contributions To Background Reduction And Computer Simulations For Cuore & Cuore-0, Ivo J. Plamenac
Physics
CUORE and CUORE-0 aim to observe neutrinoless double beta decay in 130Te; observing such this particular decay would substantiate the Majorana model for the neutrino and expand our current understanding of particle physics. This report will provide an overview of the Standard Model, our current framework for particle interactions, as well as the technical details of the CUORE experiment. Over the summers of 2010 and 2011, I contributed to the efforts of the CUORE collaboration by assisting in aspects such as background reduction, and explored detector behavior using computer simulations.
Spin Dependence In Polarized Proton-Proton Elastic Scattering At Rhic,
2013
Old Dominion University
Spin Dependence In Polarized Proton-Proton Elastic Scattering At Rhic, Donika Plyku
Physics Theses & Dissertations
The STAR (Solenoidal Tracker At RHIC - Relativistic Heavy Ion Collider) experiment is equipped with Roman Pots, insertion devices that allow detectors to be moved close to the beam for the measurement of high energy protons scattered at very small angles. This setup, together with the unique capability of RHIC to collide spin-polarized proton beams, allows STAR to study both the dynamics and the spin-dependence of the proton-proton ( pp) elastic scattering process. Silicon strip detectors, installed inside the Roman Pots, measure tracks of protons scattered diffractively at very small angles. In a dedicated run with special beam optics …
Double Spin Asymmetry In D →(E→E'P)N,
2013
Old Dominion University
Double Spin Asymmetry In D →(E→E'P)N, Michael Mayer
Physics Theses & Dissertations
Using the CLAS detector at Jefferson Lab, double spin asymmetries (A ∥) for quasi-elastic electron scattering off the deuteron have been measured at several beam energies. The data were collected during the EG1 experiment, which scattered longitudinally polarized electrons with energies from 1.6 to 5.8 GeV off a longitudinally polarized cryogenic ND3 target. The double spin asymmetries were measured as a function of photon virtuality Q2 (0.13-3.17 (GeV/c)2), missing momentum (0.0-0.5 GeV/c), and the angle between the (inferred) "spectator" neutron and the momentum transfer direction (θng). The results from EG1b are compared with a recent model …
