Author: Kazimi, R.
Paper Title Page
TUP025 Two Wien Filter Spin Flipper 862
 
  • J.M. Grames, P.A. Adderley, J. F. Benesch, J. Clark, J. Hansknecht, R. Kazimi, D. Machie, M. Poelker, M.L. Stutzman, R. Suleiman, Y. Zhang
    JLAB, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A new 4pi spin manipulator composed of two Wien filters oriented orthogonally and separated by two solenoids has been installed at the CEBAF/Jefferson Lab photoinjector. The new spin manipulator is used to precisely set the electron spin direction at an experiment in any direction (in or out of plane of the accelerator) and provides the means to reverse, or flip, the helicity of the electron beam on a daily basis. This reversal is being employed to suppress systematic false asymmetries that can jeopardize challenging parity violation experiments that strive to measure increasingly small physics asymmetries [*,**,***]. The spin manipulator is part of the ultra-high vacuum polarized electron source beam line and has been successfully operated with 100keV and 130keV electron beam at high current (>100 microAmps). A unique feature of the device is that spin-flipping requires only the polarity of one solenoid magnet be changed. Performance characteristics of the Two Wien Filter Spin Flipper will be summarized.
* http://hallaweb.jlab.org/parity/prex/
** http://www.jlab.org/qweak/
*** http://hallaweb.jlab.org/12GeV/Moller/
 
 
WEP085 Beam Breakup Studies for New Cryo-Unit 1633
 
  • S. Ahmed, F.E. Hannon, A.S. Hofler, R. Kazimi, G.A. Krafft, F. Marhauser, B.C. Yunn
    JLAB, Newport News, Virginia, USA
  • I. Shin
    University of Connecticut, Storrs, Connecticut, USA
 
  In this paper, we report the numerical simulations of cumulative beam breakup studies for a new cryo-unit for injector design at Jefferson lab. The system consists of two 1-cell and one 7-cell superconducting RF cavities. The study has been performed using a 2-dimensional time-domain code TDBBU developed in-house. The stability has been confirmed for the present setup of beamline elements with different initial offsets and currents ranging 1 mA - 100 mA.  
 
WEP288 Optimizing the CEBAF Injector for Beam Operation with a Higher Voltage Electron Gun 2023
 
  • F.E. Hannon, A.S. Hofler, R. Kazimi
    JLAB, Newport News, Virginia, USA
 
  Recent developments in the DC gun technology used at CEBAF have allowed an increase in operational voltage from 100kV to 130kV. In the near future this will be extended further to 200kV with the purchase of a new power supply. The injector components and layout at this time have been designed specifically for 100kV operation. It is anticipated that with an increase in gun voltage and optimization of the layout and components for 200kV operation, that the electron bunch length and beam brightness can be improved upon. This paper explores some upgrade possibilities for a 200kV gun CEBAF injector through beam dynamic simulations.