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Showing 1 to 20 of 31 for “"CEBAF"”.
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CEBAF Upgrade Bunch Length Measurements
… length is important for efficient operations. CEBAF needs a suitable bunch length because bunches that are too long will result in beam interruption to the halls due to excessive energy spread and beam loss. In this work, bunch length is measured by invasive and non-invasive techniques at …
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Feasibility and Conceptual Design of a C.W. Positron Source at CEBAF
… positrons. An admittance study was done at CEBAF to find the maximum phase space area, which is tolerated in the machine. The measured geometrical transverse admittance (A) were A<sub><em>x</em></sub> =10 and A<sub><em>y</em></sub> = 5 mm·mrad at the injector. Energy spread measurement was …
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Measurement of a weak polarization sensitivity to the beam orbit of the CEBAF accelerator
… experiment was performed using the CEBAF accelerator of the Thomas Jefferson National Accelerator Facility to investigate a predicted sensitivity of the beam polarization to the vertical betatron orbit in the recirculation arcs. This is the first measurement of any such effect at …
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Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector linac
… Q of the cavity higher-order modes (HOMs). The CEBAF accelerator, which employs five pass recirculation through two superconducting linacs to accelerate high CW current (up to 200 $\mu$A), poses unique instability problems. An experimental investigation of multipass BBU at CEBAF has been …
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Experimental studies of multipass beam breakup and energy recovery using the CEBAF injector LINAC
… Q of the cavity higher-order modes (HOMs ). The CEBAF accelerator, which employs five pass recirculation through two superconducting linacs to accelerate high CW current (up to 200 pA), poses unique instability problems. An experimental investigation of multipass BBU at CEBAF has been completed …
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Precision measurement of neutron spin asymmetry An1 at large xBj using CEBAF at 5.7 GeV
Nucleon spin structure has remained one of the key issues of hadronic physics since the 1980's. Among the unsolved questions, the neutron spin structure in the valence quark region (the large Bjorken variable XBj region) is of particular interest. The few data that existed in the large XBj region …
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Beyond the Born Approximation: A Precise Comparison of e+p and e-p Elastic Scattering in the CEBAF Large Acceptance Spectrometer (CLAS)
… +<em>p/e</em>− <em>p</em> ratio using the CEBAF large acceptance spectrometer (CLAS). Due to the luminosity constraint our kinematic coverage is limited to low <em>Q</em>² and high ϵ (longitudinal polarization of the virtual photon). We continued our background study through GEANT4 …
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Some Aspects of Deeply Virtual Compton Scattering
… virtual Compton scattering for the kinematics of CEBAF at Jefferson Lab.</p>
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Measurement of the Deeply Virtual Compton Scattering Cross Section from the Proton at 10.6 GeV using the CLAS12 Detector
… its background, Bethe-Heitler (BH) process. The CEBAF Large Acceptance Spectrometer for operation at 12 GeV beam en-ergy (CLAS12) collaboration has taken electron-proton scattering data in fall 2018 using a liquid hydrogen target and the 10.6 GeV polarized electron beam from the Continuous …
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Investigations of the physical properties of photoemission polarized electron sources for accelerator applications
… keV electron beam passing through the Illinois/CEBAF polarized electron injection system was studied by measuring the beam emittance as a function of current. Finally, the thermal properties of GaAs were investigated by measuring the beam emittance as functions of the excitation laser wavelength …
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A survey of beam asymmetries in semi-exclusive electron scattering on helium-4 and carbon-12
… of energies between 2.2 and 4.4 GeV, with the CEBAF Large Acceptance Spectrometer (CLAS) detector located in Hall B at the Jefferson Laboratory, VA. The measured asymmetries compare well with the theoretical predictions.</p>
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A new surface resistance measurement method with ultrahigh sensitivity
… is 1.5 GHz, the same as the working frequency of CEBAF cavities. The cavity has a compact size compared to its TE₀₁₁ counterpart, which makes it more sensitive to the sample's loss.
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Magnetic Field Shielding For the Forward Time of Flight Upgrade At Jefferson National Lab
… Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS). These detectors must be properly shielded from magnetic fields used in the manipulation of the particle trajectories during experiments. Dr. Gothe's nuclear physics group has been experimenting with …
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High energy two-body deuteron photodisintegration
… angles ϴcm=37°, 53°, 70°, and 90° as part of CEBAF experiment E89-012. Constituent counting rules predict a scaling of this cross section at asymptotic energies. In previous experiments this scaling has surprisingly been observed at energies between 1.4 and 2.8 GeV at 90°. The results from …
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Spin structure of the proton and the Q² evolution of the Gerasimov-Drell-Hearn integral
… up to 2GeV. The measurement was performed at the CEBAF Large Acceptance Spectrometer (CLAS) of the Thomas Jefferson National Accelerator Facility during the Fall of 1998. A cryogenic NH3 target was used as a source of protons polarized in the direction of the incident electron beam. For the first …
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High Energy Two -Body Deuteron Photodisintegration
… 53°, 70°, and 90° as part of CEBAF experiment E89-012. Constituent counting rules predict a scaling of this cross section at asymptotic energies. In previous experiments this scaling has surprisingly been observed at energies between 1.4 and 2.8 GeV at 90°. The results from …
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Measurement of Pion-Pion Final State Interactions in η → π +π −γ with CLAS at Jefferson Lab
… collected during the g11a run period using the CEBAF Large Acceptance Spectrometer located in Hall B at the Thomas Jefferson National Accelerator Facility in 2004. The data was collected using a tagged photon beam with energy range of 1.5-3.5 GeV incident on a liquid Hydrogen target. Our results …
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Single and Double Spin Asymmetries for Pion Electro-Production From the Deuteron in the Resonance Region
… The final state particles were detected in the CEBAF Large Acceptance Spectrometer (CLAS). The d(e,e'π-p)p exclusive channel was identified using the missing mass technique and the asymmetries were extracted as a function of the momentum transfer <em>Q</em><sup>2</sup>, invariant mass …
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Measurement of Exclusive Photo-Production of K+ Σ*- Quasi-Free off Neutrons In Deuterium
… Jefferson National Laboratory (JLab) by using the CEBAF Large Acceptance Spectrometer (CLAS) detector system and the tagger system during the EG3 run period from December 2004 to February 2005. Tagged photons with energies from 1.5 to 5.5 GeV are measured in coincidence with K <sup>+</sup> p …
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Virtual Compton Scattering Processes in Quantum Chromodynamics
… virtual Compton scattering for the kinematics of CEBAF at Jefferson Lab.</p>
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