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

Nuclear Commons™

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

2009

Discipline
Institution
Keyword
Publication
Publication Type

Articles 31 - 38 of 38

Full-Text Articles in Nuclear

Virtual Compton Scattering And Neutral Pion Electroproduction In The Resonance Region Up To The Deep Inelastic Region At Backward Angles, G. Laveissiere, N. Degrande, S. Jaminion, C. Jutier, L. Todor, G. E. Dodge, C. E. Hyde, K. Mccormick, P. E. Ulmer, L. B. Weinstein, Jefferson Lab Hall A Collaboration Jan 2009

Virtual Compton Scattering And Neutral Pion Electroproduction In The Resonance Region Up To The Deep Inelastic Region At Backward Angles, G. Laveissiere, N. Degrande, S. Jaminion, C. Jutier, L. Todor, G. E. Dodge, C. E. Hyde, K. Mccormick, P. E. Ulmer, L. B. Weinstein, Jefferson Lab Hall A Collaboration

Physics Faculty Publications

We have made the first measurements of the virtual Compton scattering (VCS) process via the H(e, e′p)γ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the W-dependence at fixed Q2=1 GeV2 and for the Q2 dependence at fixed W near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed Q2 dependence is smooth. The measured ratio of H(e, e′p)γ to H(e, e′p)π0 cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared …


Electroproduction Of P Π⁺Π⁻ Off Protons At 0.2 < Q² < 0.6 Gev² And 1.3 < W < 1.57 Gev With The Clas Detector, M. J. Amaryan, H. Baghdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde, W. Kim, A. Klein, F. J. Klein, A. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration Jan 2009

Electroproduction Of P Π⁺Π⁻ Off Protons At 0.2 < Q² < 0.6 Gev² And 1.3 < W < 1.57 Gev With The Clas Detector, M. J. Amaryan, H. Baghdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde, W. Kim, A. Klein, F. J. Klein, A. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process ep → e'pπ+π-. The data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the as yet unexplored kinematic region of photon virtuality 0.2 < Q2 < 0.6 GeV2 and invariant mass of the final hadron system W from 1.3 to 1.57 GeV. For the first time, nine independent one-fold differential cross sections were determined in each bin of W and Q2 covered by the measurements. A phenomenological analysis of the data allowed …


The Potential Contribution Of Organic Salts To New Particle Growth, Kelley Barsanti, Peter H. Mcmurry, J. N. Smith Jan 2009

The Potential Contribution Of Organic Salts To New Particle Growth, Kelley Barsanti, Peter H. Mcmurry, J. N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

Field and lab measurements suggest that low-molecular weight (MW) organic acids and bases exist in accumulation and nucleation mode particles, despite their relatively high pure-liquid vapor pressures. The mechanism(s) by which such compounds contribute to the mass growth of existing aerosol particles and newly formed particles has not been thoroughly explored. One mechanism by which low- MW compounds may contribute to new particle growth is through the formation of organic salts. In this paper we use thermodynamic modeling to explore the potential for organic salt formation by atmospherically relevant organic acids and bases for two system types: one in which …


Evaluation Of Extraction Chromatography Resins For Rapid Actinide Analysis, Julie Marisa Gostic Jan 2009

Evaluation Of Extraction Chromatography Resins For Rapid Actinide Analysis, Julie Marisa Gostic

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, physical and chemical parameters associated with extraction chromatography separation procedures were investigated for rapid actinide analysis. A vacuum box system was designed in-house and was characterized in terms of flow rate reproducibility, matrix effects on flow rate for sequential elution, and actinide separation efficiency using different types of resin (TEVA, DGA and TRU). Results indicated that the columnar kinetics of the resins were sufficiently rapid to run high purity samples through the unit over a wide range of flow rates for all resin types. Single matrix interferences at a metal ion ratio of 1:10 6 relative to …


Optimization Of The Microprecipitation Procedure For Nuclear Forensics Applications, Lyndsey Renee Kelly Jan 2009

Optimization Of The Microprecipitation Procedure For Nuclear Forensics Applications, Lyndsey Renee Kelly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Microprecipitation has become one of the most widely used sample preparation techniques for alpha spectroscopy. Many factors during the precipitation process can affect the yield and energy resolution by adding unwanted mass to the sample. Current applications in nuclear forensics call for an optimization of energy resolution and yield in order to improve identification and quantify specific radionuclides. The purpose of this research is to determine the optimal parameters used for microprecipitation. The optimal solution temperature, precipitation time, carrier amount, and hydrofluoric acid amount are used to investigate the influence of varying the type of carrier, as well as, the …


Search For The Photoexcitation Of Exotic Mesons In The Π+Π+Π- System, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, S. Bektasoglu, S. Bültmann, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, L. M. Qin, S. Tkachenko, L. B. Weinstein, J. Zhang Jan 2009

Search For The Photoexcitation Of Exotic Mesons In The Π+Π+Π- System, Clas Collaboration, M. J. Amaryan, H. Bagdasaryan, S. Bektasoglu, S. Bültmann, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, J. Lachniet, M. R. Niroula, L. M. Qin, S. Tkachenko, L. B. Weinstein, J. Zhang

Physics Faculty Publications

A search for exotic mesons in the π+π+π− system photoproduced by the charge exchange reaction γp→π+π+π−(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the …


Spin Structure Of The Deuteron, Nevzat Guler Jan 2009

Spin Structure Of The Deuteron, Nevzat Guler

Physics Theses & Dissertations

Double spin asymmetries for the proton and the deuteron have been measured in the EG1b experiment using the CLAS detector at Jefferson Lab. Longitudinally polarized electrons at energies 1.6, 2.5, 4.2 and 5.7 GeV were scattered from longitudinally polarized NH3 and ND3 targets. The double spin asymmetry A|| for the proton and the deuteron has been extracted from these data as a function of W and Q2 with unprecedented precision. The virtual photon asymmetry A1 and the spin structure function g1 can be calculated from these measurements by using parametrization to the world data for the virtual …


Neutron Structure Functions Measured With Spectator Tagging, Svyatoslav Tkachenko Jan 2009

Neutron Structure Functions Measured With Spectator Tagging, Svyatoslav Tkachenko

Physics Theses & Dissertations

We know much less about the neutron than the proton due to the absence of free neutron targets. Neutron information has to be extracted from data on nuclear targets like deuterium. This requires corrections for off-shell and binding effects which are not known from first principles and therefore are model-dependent. As a consequence, the same data can be interpreted in different ways, leading to different conclusions about important questions such as the value of the d/u quark ratio at large momentum fraction x. The Barely Off-shell NUcleon Structure (BONUS) experiment at Jefferson Lab addressed this problem by tagging spectator protons …