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Steier, C.

Paper Title Page
WEPCH102 Studies of the Nonlinear Dynamics Effects of APPLE-II Type EPUs at the ALS 2152
 
  • C. Steier, S. Marks, S. Prestemon, D. Robin, D. Schlueter, W. Wan, W. Wittmer
    LBNL, Berkeley, California
 
  Elliptically Polarizing Undulators (EPUs) have become more and more popular at synchrotron radiation sources, providing full polarization control of the photon beam. The fields of the most commonly used APPLE-II type EPUs have a very fast, intrinsic field roll-off, creating significant non-linearities of the beam motion with in some cases large impact on the dynamic (momentum) aperture. In general, the nonlinear effects get stronger with longer periods and higher undulator magnetic fields. One of the planned future beamlines at the ALS (MERLIN) will use a quasiperiodic EPU with 9 cm period and maximum B fields of about 1.3 T. We will present simulation studies for the proposed shimming schemes for this future device to reduce the nonlinear effects to acceptable values, as well as experimental studies for the existing 5 cm period EPUs already installed in the ALS.  
THPLS082 Status of the Top-off Upgrade of the ALS 3469
 
  • C. Steier, D. Robin, T. Scarvie
    LBNL, Berkeley, California
 
  In order to provide higher brightness and better stability, the ALS is being upgraded to top-off injection. One main part of the top-off modifications is an upgrade of the booster as well as extraction and injection elements and the transfer line for full energy. Further upgrades include new diagnostics, improved controls and timing system, and new radiation safety systems (monitors and interlocks).