Author: Beutner, B.
Paper Title Page
TUP002 Numerical Studies on RF-Induced Trajectory Variations at the European XFEL 1
 
  • T. Hellert, B. Beutner, W. Decking, N. Walker
    DESY, Hamburg, Germany
 
  At the European X-Ray Free-Electron Laser, superconducting TESLA-type cavities are used for acceleration of the driving electron bunches. Due to the high achievable duty cycle, a long radio frequency (RF) pulse structure can be provided, which allows to operate the machine with long bunch trains. The designated pointing stability of the FEL radiation places stringent restrictions on the acceptable trajectory variations of individual electron bunches. Therefore a transverse intra-bunch-train feedback system (IBFB) is located upstream of the undulator section. However, intra-bunch-train variations of RF parameters and misalignment of RF structures induce significant trajectory variations that may exceed the capability of the IBFB. In this paper we give an estimate of the expected RF-induced intra-bunch-train trajectory variations for different machine realizations and investigate methods for their limitation.  
 
TUP003 First Beam Halo Measurements Using Wire Scanners at the European XFEL 1
 
  • S. Liu, V. Balandin, B. Beutner, W. Decking, L. Fröhlich, N. Golubeva, T. Lensch
    DESY, Hamburg, Germany
 
  Beam halo measurements and collimations are of great importance at the European XFEL, especially for the operation at high repetition rates (27000 pulses/s). First beam halo measurements have been performed during the commissioning using the wire scanners installed before and after the ~200 m long post-linac collimation section. We present the measurement results and the comparison of beam halo distributions before and after the collimation section.  
 
TUP005 Studies of the Transverse Beam Coupling in the European XFEL Injector 1
 
  • M. Scholz, B. Beutner
    DESY, Hamburg, Germany
 
  Coupling between the transverse plains leads to an increase of the horizontal and vertical electron beam emittances. The coupling can be measured with dedicated multi quadrupole scans while the correlations of the beam are observed on a screen. In this paper we show the results from first coupling studies in the European XFEL injector.  
 
WEA01
European XFEL Injector Commissioning Results  
 
  • B. Beutner
    DESY, Hamburg, Germany
 
  In the first commissioning phase of the European XFEL SASE FEL driver linac, we demonstrated the design goals for the injector section. These goals include reliable operation of sub-systems and feasible beam parameters like emittance and bunch length of the beam produced by the RF gun. Of particular interest is the operation of long bunch trains with up to 2700 bunches with a 4.5 MHz repetition rate. In this presentation we will provide an overview of our experiences from the injector commissioning run including beam dynamics studies, diagnostics, and system performance.  
slides icon Slides WEA01 [4.628 MB]