Nuclear Commons^™

A Measurement Of The Parity Violating Asymmetry In The Neutron Capture On 3He At Sns, Md Latiful Kabir

Theses and Dissertations--Physics and Astronomy

Weak nucleon nucleon couplings are largely unknown because of the involved theoretical and experimental challenges. Theoretically the topic is difficult due to the non-perturbative nature of the strong interaction, which makes calculations of the couplings challenging. Experimentally, the topic is difficult given that 1) the observables are determined by ratios between strong couplings and weak couplings which differ in size by seven orders of magnitude, and 2) theoretically clean and predictable measurements are almost always restricted to simple systems that do not allow for effects that enhance the size of the asymmetry. However parity violation (PV) can be used to …

A Study Of The Potential Applications Of Am241, And Determining The Feasibility Of Using Gamma Spectroscopy For Future Physical Validation, Eric A. Feissle

Masters Theses

“Am241 is typically produced via Pu241 decay in a uranium fueled reactor. Presence of Am241 can be used as the age estimation tool for spent fuel, which is a focus of this thesis along with the interest of the measurement and the ratio of production rates of Am241’s activation products; Americium-242 and its first excited state of Americium-242m. MCNP models of the core and BEGe 3825 detector were built. These models were compared with established and physical measurements of gamma/x-ray standards that were available at the reactor. Thermal fluxes at 200 kW for potential foils centered in the source holder …

Measurements Of Ep → E′Π+Π-P′ Cross Sections With Clas At 1.40 Gev < W < 2.0 Gev And 2.0 Gev² < Q² < 5.0 Gev², E.L. Isupov, V.D. Burkert, D.S. Carman, R. W. Gothe, R. Hicks, B. S. Ishkhanov, V. I. Mokeev, K. P. Adhikari, S. Adhikari, D. Adikaram, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, B. Torayev

Physics Faculty Publications

This paper reports new exclusive cross sections for ep → e′π⁺π^-p′ using the CLAS detector at Jefferson Laboratory. These results are presented for the first time at photon virtualities 2.0GeV² 2 < 5.0GeV² in the center-of-mass energy range 1.4 GeV < W < 2.0 GeV, which covers a large part of the nucleon resonance region. Using a model developed for the phenomenological analysis of electroproduction data, we see strong indications that the relative contributions from the resonant cross sections at W < 1.74 GeV increase with Q². These data considerably extend the kinematic reach of previous measurements. Exclusive ep → e′π⁺π^-p′ cross section measurements are of particular importance for the extraction of resonance electrocouplings in the mass range above 1.6 GeV.

Photon Beam Asymmetry Σ In The Reaction →Γ P → Pω For Eγ = 1.152 To 1.876 Gev, P. Collins, B. G. Ritchie, M. Dugger, F. J. Klein, A. V. Anisovich, E. Klempt, V. A. Nikonov, A. Sarantsev, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ → p → ω p are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson …

Measurement Of The Helicity Asymmetry E In Ω→Π+ΠˉΠᵒ Photoproduction, Z. Akbar, P. Roy, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, V. A. Nikonov, A. V. Sarantsev, K. P. Adhikari, M. J. Amaryan, G. Charles, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

The double-polarization observable E was studied for the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω→π⁺π^-π⁰, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2⁺ partial wave near threshold, which is identified with the subthreshold N(1720)3/2⁺ nucleon …

Extraction Of The Nuetron Electric Form Factor From Measurements Of Inclusive Double Spin Asymmetries, V. Sulkosky, G. Jin, E. Long, Y.W. Zhang, M. Mihovilovic, A. Kelleher, B. Anderson, D. W. Higinbotham, S. Ŝirca, K. Allada, M. Canan

Physics Faculty Publications

Background: Measurements of the neutron charge form factor, Gⁿ_E , are challenging because the neutron has no net charge. In addition, measurements of the neutron form factors must use nuclear targets which require accurately accounting for nuclear effects. Extracting Gⁿ_E with different targets and techniques provides an important test of our handling of these effects.

Purpose: The goal of the measurement was to use an inclusive asymmetry measurement technique to extract the neutron charge form factor at a four-momentum transfer of 1(GeV/c)² . This technique has very different systematic uncertainties than traditional exclusive …

Target Mass Effects In Parton Quasi-Distributions, A. V. Radyushkin

Physics Faculty Publications

We study the impact of non-zero (and apparently large) value of the nucleon mass M on the shape of parton quasi-distributions Q(y, p₃), in particular on its change with the change of the nucleon momentum p_3. We observe that the usual target-mass corrections induced by the M-dependence of the twist-2 operators are rather small. Moreover, we show that within the framework based on parametrizations by transverse momentum dependent distribution functions (TMDs) these corrections are canceled by higher-twist contributions. We identify a novel source of kinematic target-mass dependence of TMDs and build models corrected for …

First Measurement Of Unpolarized Semi-Inclusive Deep-Inelastic Scattering Cross Sections From A He 3 Target, X. Yan, K. Allada, K. Aniol, J. R. M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P. C. Bradshaw, P. Bosted, A. Camsonne, M. Canan

Physics Faculty Publications

The unpolarized semi-inclusive deep-inelastic scattering (SIDIS) differential cross sections in ³He(e,e′π^±)X have been measured for the first time in Jefferson Lab experiment E06-010 with a 5.9GeV e- beam on a ³He gas target. The experiment focuses on the valence quark region, covering a kinematic range 0.12<x_bj<0.45,1<Q²<4(GeV/c)²,0.45<z_h<0.65, and 0.05<P_t<0.55GeV/c. The extracted SIDIS differential cross sections of π^± production are compared with existing phenomenological models while the ³He nucleus approximated as two protons and one neutron in a plane-wave picture, in multidimensional bins. Within …

Photon Beam Asymmetry Σ For Η And Η′ Photoproduction From The Proton, P. Collins, B. G. Ritchie, M. Dugger, A. V. Anisovich, M. Doring, E. Klempt, V. A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, M. J. Amaryan, A. Klein

Physics Faculty Publications

Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η ′ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the γ p → η p reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γ p → η ′ p reaction. For γ p → η p , the data reported here considerably extend the range of measurements to higher energies, and are …

Measurement Of Two-Photon Exchange Effect By Comparing Elastic E ± P Cross Sections, D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, A. V. Afanasev, Z. Akbar

Physics Faculty Publications

Background: The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four-momentum transfer (Q²) . Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed.

Purpose: We measured the ratio of positron-proton to electron-proton elastic-scattering cross …

Differential Cross Section Measurements For Γn→Π-P Above The First Nucleon Resonance Region, P. T. Mattione, D. S. Carman, I. I. Strakovsky, R. L. Workman, A. E. Kudryavtsev, A. Svarc, V. E. Tarasov, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, Z. W. Zhao

Physics Faculty Publications

The quasifree γd→π^-p(p) differential cross section has been measured with CLAS at photon beam energies E_γ from 0.445 to 2.510 GeV (corresponding to W from 1.311 to 2.366 GeV) for pion center-of-mass angles cosθπc.m. from -0.72 to 0.92. A correction for final state interactions has been applied to these data to extract the γn→π^-p differential cross sections. These cross sections are quoted in 8428 (E_γ,cosθπc.m.) bins, a factor of nearly 3 increase in the world statistics for this channel in this kinematic range. These new data …

Determination Of The Proton Spin Structure Functions For 0.05 < Q2 <5gev2 Using Clas, R. G. Fersch, N. Guler, P. Bosted, A. Deur, K. Griffioen, C. Keith, S E. Kuhn, R. Minehart, Y. Prok, K. P. Adhikari, S. Bültmann, S. Careccia, Gail Dodge, V. G. Lagerquist, L. B. Weinstein

Physics Faculty Publications

We present the results of our final analysis of the full data set of g^p₁ Q², the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets ¹⁵NH₃ dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries A^p₁ and A^p₂ and spin structure functions g ^p₁ and g^p₂ over a wide kinematic range (0.05 GeV …

Measurement Of The Differential And Total Cross Sections Of The ᵧd→Kºʌ(P) Reaction Within The Resonance Region, N. Compton, C. E. Taylor, K. Hicks, P. Cole, N. Zachariou, Y. Ilieva, P. Nadel-Turonski, E. Klempt, V. A. Nikonov, A. V. Sarantsev, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, B. Torayev, J. Zhang

Physics Faculty Publications

We report the first measurement of differential and total cross sections for the γd →K⁰ Λ(p)reaction, using data from the CLAS detector at the Thomas Jefferson National Accelerator Facility. Data collected during two separate experimental runs were studied with photon-energy coverage 0.8-3.6 GeV and 0.5-2.6 GeV, respectively. The two measurements are consistent giving confidence in the method and determination of systematic uncertainties. The cross sections are compared with predictions from the KAON-MAID theoretical model (without kaon exchange), which deviate from the data at higher W and at forward kaon angles. These data, along with previously published cross sections for …

Nucleon-Nucleon Correlations, Short-Lived Excitations, And The Quarks Within, Or Hen, Gerald A. Miller, Eli Piasetzky, Lawrence B. Weinstein

Physics Faculty Publications

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. The interpretation of measurements of the European Muon Collaboration (EMC) effect for valence quarks, a reduction in the deep inelastic scattering cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon short-range correlations (SRCs) in nuclei are focused on. This review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and …

Target And Beam-Target Spin Asymmetries In Exclusive Pion Electroproduction For Q² > 1 Gev² . Ii. Ep→ Eπºp, Clas Collaboration, K. P. Adhikari, D. Adikaram, M. J. Amaryan, S. Bültmann, N. Guler, S E. Kuhn, A. Klein, S. Koirala, B. Torayev, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π⁰ electroproduction reaction γ^∗p→pπ⁰, expanding an analysis of the γ^∗p→nπ⁺ reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 < W < 3 GeV and 1 < Q²< 6 GeV² . Results were obtained for about 5700 bins in W, Q², cos(θ^∗) , and ϕ^∗. The beam-target asymmetries were found to generally be greater than zero, with …

Optimization Of The Rf Cavity Heat Load And Trip Rates For Cebaf At 12 Gev, H. Zhang, Y. Roblin, A. Freyberger, G. Krafft, B. Terzić

Physics Faculty Publications

The Continuous Electron Beam Accelerator Facility at JLab has 200 RF cavities in the north linac and the south linac respectively after the 12 GeV upgrade. The purpose of this work is to simultaneously optimize the heat load and the trip rate for the cavities and to reconstruct the pareto-optimal front in a timely manner when some of the cavities are turned down. By choosing an efficient optimizer and strategically creating the initial gradients, the pareto-optimal front for no more than 15 cavities down can be re-established within 20 seconds.

Improving Nuclear Safety, Security, And Nonproliferation In Northeast Asia Through Multinational Approach, Viet Phuong Nguyen

International Journal of Nuclear Security

No abstract provided.

Nuclear Power: Black Sky Liability Or Black Sky Asset?, Sherrell R. Greene

International Journal of Nuclear Security

Ready access to abundant electricity is a key enabler of modern life. During the past decade the vulnerability of Critical Infrastructure sectors in the U.S. to a variety of natural hazards and man-made threats has become increasingly apparent. The electrical infrastructure (the “Grid”) is the foundation for all other critical civil infrastructures upon which our society depends. Therefore, protection of the Grid is an energy security, homeland security, and national security issue of highest importance. Geomagnetic disturbances (GMD) induced by solar coronal mass ejections (CMEs), electromagnetic pulse (EMP) attacks, and cyber attacks are three events having the potential to plunge …

Addressing The Tunnel Threat At Nuclear Facilities: A Case Study, Md. Mobasher Ahmed

International Journal of Nuclear Security

No abstract provided.

Janus Realized: The Use Of Social Media As A Means Of Transparency Nuclear Communication To The Public, Frances Bachstein

International Journal of Nuclear Security

No abstract provided.