R. Suleiman
A5024044375- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- Nuclear physics research studies
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Electron and X-Ray Spectroscopy Techniques
- Plasma Diagnostics and Applications
- Dark Matter and Cosmic Phenomena
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Radiation Therapy and Dosimetry
- Gyrotron and Vacuum Electronics Research
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Laser Design and Applications
- Crystallography and Radiation Phenomena
- Advanced Optical Sensing Technologies
- Magnetic confinement fusion research
- High-Energy Particle Collisions Research
- Advanced Electron Microscopy Techniques and Applications
- Advanced Chemical Physics Studies
Thomas Jefferson National Accelerator Facility
2015-2024
Old Dominion University
2018-2020
Xelera Research (United States)
2019
Cornell University
2018
Argonne National Laboratory
2017
Virginia Tech
2010-2012
Massachusetts Institute of Technology
2003-2007
Kent State University
1998-1999
We report new measurements of the parity-violating asymmetry ${A}_{\mathrm{PV}}$ in elastic scattering 3 GeV electrons off hydrogen and $^{4}\mathrm{He}$ targets with $⟨{\ensuremath{\theta}}_{\mathrm{lab}}⟩\ensuremath{\approx}6.0\ifmmode^\circ\else\textdegree\fi{}$. The result is ${A}_{\mathrm{PV}}=\mathbf{(}+6.40\ifmmode\pm\else\textpm\fi{}0.23(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.12(\mathrm{syst})\mathbf{)}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$....
The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 μA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target Jefferson Lab. results experiment's commissioning run, constituting approximately 4% data collected experiment, are reported here. From these initial results, is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which smallest and most precise ever scattering. small Q(2) this made possible...
We have measured parity-violating asymmetries in elastic electron-proton and quasielastic electron-deuteron scattering at ${Q}^{2}=0.22$ $0.63\text{ }\text{ }{\mathrm{GeV}}^{2}$. They are sensitive to strange quark contributions currents the nucleon axial-vector current. The results indicate of $\ensuremath{\lesssim}10%$ charge magnetic form factors these four-momentum transfers. also present first measurement anapole moment effects current
The Polarized Electrons for Positrons experiment at the injector of Continuous Electron Beam Accelerator Facility has demonstrated first time efficient transfer polarization from electrons to positrons produced by polarized bremsstrahlung radiation induced a electron beam in high-Z target. Positron up 82% have been measured an initial momentum 8.19 MeV/c, limited only polarization. This technique extends positron capabilities GeV MeV beams, and opens access physics wide community.
We have measured the parity-violating electroweak asymmetry in elastic scattering of polarized electrons from 4He at an average angle <theta(lab)> = 5.7 degrees and a four-momentum transfer Q2 0.091 GeV2 . From these data, for first time, strange electric form factor nucleon G(E)s can be isolated. The A(PV) (6.72 +/- 0.84(stat) 0.21(syst) x 10(-6) yields value -0.038 0.042(stat) 0.010(syst), consistent with zero.
We report the most precise measurement to date of a parity-violating asymmetry in elastic electron-proton scattering. The was carried out with beam energy 3.03 GeV and scattering angle =6 degrees, result A_PV = -1.14 +/- 0.24 (stat) 0.06 (syst) parts per million. From this we extract, at Q^2 0.099 GeV^2, strange form factor combination G_E^s + 0.080 G_M^s 0.030 0.025 0.006 0.012 (FF) where first two errors are experimental last error is due uncertainty neutron electromagnetic factor. This...
A new dc high voltage spin-polarized photoelectron gun has been constructed that employs a compact inverted-geometry ceramic insulator. Photogun performance at 100 kV bias is summarized.Received 24 November 2009DOI:https://doi.org/10.1103/PhysRevSTAB.13.010101This article available under the terms of Creative Commons Attribution 3.0 License. Further distribution this work must maintain attribution to author(s) and published article's title, journal citation, DOI.
GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed average current facilities that operate tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and minimize the ill effects ion bombardment, dominant mechanism reduces yield photogun. Experimental results presented here demonstrate...
The physics case and an experimental overview of the MOLLER (Measurement Of a Lepton Electroweak Reaction) experiment at 12 GeV upgraded Jefferson Lab are presented. A highlight Fundamental Symmetries subfield 2007 NSAC Long Range Plan was SLAC E158 measurement parity-violating asymmetry $A_{PV}$ in polarized electron-electron (M{\o}ller) scattering. proposed will improve on this result by factor five, yielding most precise weak mixing angle low or high energy anticipated over next decade....
A concise demonstrative summary of the Symmetric Hybrid ring design for storage proton electric dipole moment experiment is presented. Critical issues such as lattice design, background electrical fields,geometrical phase, general relativity, spin coherence time and polarimeter systematics are Overall, we find that with currently proposed iteration, systematic error sources reduced by orders magnitude alignment requirements within available technology.
Two ${\mathrm{K}}_{2}\mathrm{CsSb}$ photocathodes were manufactured at Brookhaven National Lab and delivered to Jefferson within a compact vacuum apparatus pressure $\ensuremath{\sim}{10}^{\ensuremath{-}11}\text{ }\text{ }\mathrm{Torr}$. These evaluated using dc high voltage photogun biased voltages up 200 kV, illuminated with laser light wavelengths 440 or 532 nm, generate electron beams currents 20 mA. Some conditions produced exceptionally large photocathode charge lifetimes, without...
We have measured the beam-normal single-spin asymmetries in elastic scattering of transversely polarized electrons from proton, and performed first measurement quasielastic on deuteron, at backward angles (lab angle 108°) for Q² = 0.22 GeV²/c² 0.63 beam energies 362 687 MeV, respectively. The asymmetry arises due to imaginary part interference two-photon exchange amplitude with that single-photon exchange. Results proton are consistent a model calculation which includes inelastic...
We report the first measurement of parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, ⟨E_{lab}⟩=1.157 GeV with Q_{weak} apparatus Jefferson Lab. Predictions using a simple Born approximation as well more sophisticated distorted-wave calculations are in good agreement this result. From neutron radius R_{n}=2.89±0.12 fm determined many-models...
This contribution describes the latest milestones of a multiyear program to build and operate compact $\ensuremath{-}300\text{ }\text{ }\mathrm{kV}$ dc high voltage photogun with inverted insulator geometry alkali-antimonide photocathodes. Photocathode thermal emittance measurements quantum efficiency charge lifetime at average current up 4.5 mA are presented, as well an innovative implementation ion generation tracking simulations explain benefits biased anode repel beam line ions from...
We present a new design of highly specialized small storage rings for low energy polarized electron beams. The is based on the transparent spin methodology that cancels precession due to magnetic dipole moment at any while allowing induced by fundamental physics interest accumulate. buildup vertical component beam polarization can be measured using standard Mott polarimetry optimal energy. Systematic effects are suppressed counter-rotating bunched beams with various orientations. These used...
We report on the design and performance of a Mott polarimeter optimized for nominal 5-MeV electron beam from Continuous Electron Beam Accelerator Facility (CEBAF) injector. The rf time structure this allows use flight in scattered detection, making it possible to cleanly isolate those detected electrons that originate scattering foil, resulting measured asymmetries which are exceptionally stable over broad range conditions, currents, foil thicknesses. In two separate series measurements...
We propose a new precision measurement of parity-violating electron scattering on the proton at very low Q^2 and forward angles to challenge predictions Standard Model search for physics. A unique opportunity exists carry out first proton's weak charge, $Q_W =1 - 4\sin^2θ_W$. 2200 hour parity violating asymmetry in elastic ep Q^2=0.03 (GeV/c)^2 employing 180 $μ$A 85% polarized beam 35 cm liquid Hydrogen target will determine charge with approximately 4% combined statistical systematic...
GaAs photocathodes in dc high-voltage photoguns are highly susceptible to ion back-bombardment, which reduces the photocathode quantum efficiency and limits useful operating lifetime for producing polarized electron beams. This paper demonstrates that applying a small positive bias photogun anode can significantly suppress back-bombardment increase charge lifetime. technique was studied extensively using Continuous Electron Beam Accelerator Facility photogun, where beams created...
The charge form factor of $^$4He has been extracted in the range 29 fm$^{-2}$ $\le Q^2 \le 77$ from elastic electron scattering, detecting $^4$He nuclei and electrons coincidence with High Resolution Spectrometers Hall A Facility Jefferson Lab. results are qualitative agreement realistic meson-nucleon theoretical calculations. data have uncovered a second diffraction minimum, which was predicted $Q^2$ this experiment, rule out conclusively long-standing predictions dimensional scaling...
A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to imaginary part two-photon exchange process. We report a 2% precision measurement elastic electron-proton with mean angle θ_{lab}=7.9° and energy 1.149 GeV. The result B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This most precise this quantity available date therefore provides stringent test models at far-forward angles (θ_{lab}→0) where they...
We describe a proposal to search for an intrinsic electric dipole moment (EDM) of the proton with sensitivity \targetsens, based on vertical rotation polarization stored beam. The New Physics reach is order $10^~3$TeV mass scale. Observation EDM provides best probe CP-violation in Higgs sector, at level that may be inaccessible electron-EDM experiments. improvement $\theta_{QCD}$, parameter crucial axion and dark matter physics, about three orders magnitude.
The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. measurement conducted as part the G0 experiment, beam energy 360 MeV. physics process dominating pion for these kinematics is quasifree photoproduction off neutron via Δ0 resonance. In context heavy-baryon chiral perturbation theory, this related to low-energy constant d(Δ)- that characterizes γNΔ coupling. Zhu et al. calculated model...