Author: Adderley, P.A.
Paper Title Page
TUPMA020 PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons 1878
 
  • A.H. Adeyemi, P.L. Gueye
    Hampton University, Hampton, Virginia, USA
  • P.A. Adderley, M.M. Ali, H. Areti, J. F. Benesch, L.S. Cardman, J. Clark, S. Covert, C. Cuevas, A. Freyberger, S. Golge, J.M. Grames, P.L. Gueye, J. Hansknecht, P.L. Harrell, C. Hyde, R. Kazimi, Y. Kim, D. Machie, K.L. Mahoney, R.R. Mammei, J.L. McCarter, M.D. McCaughan, M. Poelker, M.L. Stutzman, R. Suleiman, C.-Y. Tsai, D.L. Turner, Y.W. Wang
    JLab, Newport News, Virginia, USA
  • M.A. Baylac, E. Froidefond, M. Marton, J-F. Muraz, J-S. Real, E. J-M. Voutier
    LPSC, Grenoble Cedex, France
  • P. Cole, D. Dale, T.A. Forest
    ISU, Pocatello, Idaho, USA
  • O. Dadoun, A. Variola
    LAL, Orsay, France
  • D. Dale, Y. Kim
    IAC, Pocatello, Idaho, USA
  • EF. Fanchini
    INFN Genova, Genova, Italy
  • S. Golge
    NCCU, , North Carolina, USA
  • S. Golge, C. Hyde
    ODU, Norfolk, Virginia, USA
  • J.L. McCarter
    UVa, Charlottesville, Virginia, USA
  • C.-Y. Tsai
    Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
  • A. Variola
    IN2P3-CNRS, Orsay, France
  
  Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e−/e+ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA020  
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WEPWI024 Vacuum Characterization and Improvement for the Jefferson Lab Polarized Electron Source 3540
 
  • M.L. Stutzman, P.A. Adderley, M. Poelker
    JLab, Newport News, Virginia, USA
  • M.A. Mamun
    Old Dominion University, Norfolk, Virginia, USA
  
  Operating the JLab polarized electron source with high reliability and long lifetime requires vacuum near the XHV level (<=1x10-12 Torr). This paper describes ongoing vacuum research at Jefferson Lab including characterization of outgassing rates for surface coatings and heat treatments, ultimate pressure measurements, investigation of pumping including an XHV cryopump, and characterization of ionization gauges in this pressure regime.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWI024  
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