Author: Angelovski, A.
Paper Title Page
TUPC29 Grounded Coplanar Waveguide Transmission Lines as Pickups for Beam Position Monitoring in Particle Accelerators 438
  • A. Penirschke, A. Angelovski, R. Jakoby
    TU Darmstadt, Darmstadt, Germany
  • C. Gerth, U. Mavrič, D. Nölle, C. Sydlo, S. Vilcins
    DESY, Hamburg, Germany
  Funding: The work was supported by the MSK group at DESY Hamburg. The authors would like to thank the CST AG for providing the CST Software Package.
Energy beam position monitors (EBPM) based on grounded co-planar waveguide (GCPW) transmission lines have been designed for installation in the dispersive sections of the bunch compressor chicanes at the European XFEL. In combination with beam position monitors at the entrance and exit of the bunch compressor chicanes, measurements of the beam energy with single bunch resolution are feasible. The EBPM consists of transversely mounted stripline pickups in a rectangular beam pipe section. The signal detection for the measurement of the phases of the pulses at each end of the pickups is based on the standard down-conversion and phase detection scheme used for the low-level RF-system. A measurement resolution within the lower micrometer range can be achieved for input signal reflections at the pickup of less than -25 dB at 3 GHz. In this paper, simulation results of a novel pickup geometry utilized with GCPW pickup structures and optimized transitions to perpendicular mounted coaxial connectors are presented. The simulation results exhibit small reflection coefficients with reflected signal components having less than 2% of the peak voltage signal.
WEPC40 Pickup Signal Improvement for High Bandwidth BAMs for FLASH and European - XFEL 778
  • A. Angelovski, R. Jakoby, A. Penirschke
    TU Darmstadt, Darmstadt, Germany
  • M.K. Czwalinna, H. Schlarb, C. Sydlo
    DESY, Hamburg, Germany
  • T. Weiland
    TEMF, TU Darmstadt, Darmstadt, Germany
  In order to measure the arrival time of the electron bunches in low (20 pC) and high (1 nC) charge operation mode, new high bandwidth pickups were developed as a part of the Bunch Arrival-time Monitors (BAMs) for FLASH at DESY *. The pickup signal is transported via radiation resistant coaxial cables to the electro-optic modulator (EOM) **. Due to the high losses of the 40 GHz RF front-end the signal in the RF path is attenuated well below the optimal operation voltage of the EOM. To improve the overall performance, the signal strength of the induced pickup signal needs to be increased and at the same time the losses in the RF front-end significantly reduced. In this paper, the analysis towards improving the induced pickup signal strength is presented. Simulations are performed with the CST STUDIO SUITE package and the results are compared with the state of the art high bandwidth pickups.
* A. Angelovski et al., Phys. Rev. ST Accel. Beams 15, 112803 (2012)
** A. Penirschke et al., Proc. of IBIC2012, Tsukuba, Japan (2012)