Author: Lambiase, R.F.
Paper Title Page
TUPTS103 The Progress of High Current High Bunch Charge Polarized Electron HVDC Gun 2160
 
  • E. Wang, I. Ben-Zvi, R.F. Lambiase, W. Liu, O.H. Rahman, J. Skaritka, F.J. Willeke
    BNL, Upton, Long Island, New York, USA
  • I. Ben-Zvi
    Stony Brook University, Stony Brook, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The high current and high bunch charge polarized electron source is essential for cost reduction of eRHIC. It aims to deliver electron beam with 10 mA average current and 5.3 nC bunch charge. We analyzed the mechanism of cathode degradation and proposed using a large strain superlattice GaAs photocathode in a high voltage DC gun to increase the charge lifetime above kilo Coulomb. The gun has been designed and fabricated and expected to start commissioning by the mid of this year. In this paper, we will present the modeling of ion back bombardment and cathode degrading. We proposed an anode offset scheme to increase cathode lifetime. Also, we will describe the details of gun design and the strategies to demonstrate high current high charge polarized electron beam from this source. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS103  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP048 Development of Spin Rotator and an Absolute Polarimeter for Polarized He-3 at BNL 2440
 
  • D. Raparia, G. Atoian, S. Ikeda, R.F. Lambiase, M. Okamura, A. Poblaguev, J. Ritter, S. Trabocchi, A. Zelenski
    BNL, Upton, Long Island, New York, USA
  • R. Milner, M.M. Musgrave
    MIT, Cambridge, Massachusetts, USA
  
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
EBIS Preinjector will provide longitudinally polarized 3He++ ions with about 80% polarization and 5.1011 particles per bunch at 6 MeV, which must be rotated to vertical direction before it ions are injected into the Booster. The 3He++ longitudinal polarization is first rotated to the transverse direction by the 21.5° bending magnet. Then the solenoid spin-rotator rotates the spin to the vertical direction. The spin-rotator will be a pulsed solenoid with a reversible field to enable spin flips. The vertically polarized beam will be returned back to the straight HEBT line by the system of three dipole magnets after the spin rotator solenoid. The low-energy polarimeter can be installed in the straight beam line section after the second dipole magnet. To measure transverse (vertical) polarization of the 3He beam at 5-6 MeV, the spin correlated asymmetry of 3He scattering on a 4He gas target (~5 Torr) will be measured with left/right symmetric strip detectors. Paper will present status of the project. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP048  
About • paper received ※ 19 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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