Author: Bahrdt, J.
Paper Title Page
MOPPP065 Effects of Geometrical Errors on the Field Quality in a Planar Superconducting Undulator 708
  • J. Bahrdt
    HZB, Berlin, Germany
  • J. Bahrdt, Y. Ivanyushenkov
    ANL, Argonne, USA
  Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Short-period superconducting undulators are being developed at the Advanced Photon Source (APS). The first test device is being fabricated. It is using a relatively short magnetic structure that will be replaced with a longer magnet in the second device. High quality magnetic field with the phase errors at a level of 2 degrees rms were achieved in the prototype magnets due to very accurate winding of the superconducting coils on the formers machined to about 10-μm precision. Manufacturing meters-long undulator structures to such tolerances would be very difficult or even impossible. It is therefore important to understand the effects of the mechanical tolerances in the coil manufacture process on the quality of the magnetic field. The effects of geometrical errors in the position of a superconducting winding in a planar structure are simulated with the RADIA software package. A field profile of a long non-ideal undulator magnet is then built and analyzed in terms of the first and second field integrals as well as phase errors. The results of the systematic study of the geometrical errors on the field quality are presented in this paper.
MOPPP064 Challenges of Quasiperiodic APPLE Undulators 705
  • J. Bahrdt
    HZB, Berlin, Germany
  • S. Sasaki
    HSRC, Higashi-Hiroshima, Japan
  APPLE undulators have become workhorses in many synchrotron radiation facilities for the production of variably polarized light. In helical mode higher harmonics are not produced. In linear mode (horizontal, vertical, inclined) higher harmonics may contaminate the first harmonic and spoil the quality of experimental data. Planar undulators employing a quasiperiodic magnetic structure have been built and they are successfully operated at several places. The implementation of a quasiperiodic lattice in an APPLE undulator is more complicated since the device is operated in various modes of operation. The proposed APS-upgrade includes a quasiperiodic APPLE undulator which is intended to be operated in the range 2.4-27 keV. A detailed analysis of the magnetic and spectral performance of this device is presented.  
TUPPP007 Modifications to the Machine Optics of BESSY II Necessitated by the EMIL Project 1614
  • P.O. Schmid, J. Bahrdt, T. Birke, R. Follath, P. Kuske, D. Simmering, G. Wüstefeld
    HZB, Berlin, Germany
  The Helmholtz Zentrum Berlin and the Max Planck Society are going to build a new dedicated X-ray beam line at the synchrotron source light source BESSY II which will be used for analyzing materials for renewable energy generation. The new large scale project has been dubbed EMIL. In this document we present the modifications to the machine optics and to what extent these changes affect the performance of BESSY II.  
FRXAB01 Symplectic Tracking and Compensation of Dynamic Field Integrals in Complex Undulator Structures 4165
  • J. Bahrdt, G. Wüstefeld
    HZB, Berlin, Germany
  This presentation covers analytical models that describe the interaction of an electron beam with the magnetic field of undulators. Analytic approximations to the Hamilton-Jacobi equation yield generating functions useful for particle tracking and therefore efficient simulation. Analytic expressions for kick maps of APPLE II undulators are presented as well. Passive and active shimming schemes including magic fingers and current sheets are also modeled. Applications at BESSY II are discussed which ensure efficient injection during top-up to satisfy machine protection and radiation safety requirements.  
slides icon Slides FRXAB01 [1.922 MB]