Author: Peier, P.
Paper Title Page
THA01 THz Streak Camera for FELTemporal Diagnostics: Concepts and Considerations 640
  • P.N. Juranic, R. Abela, I. Gorgisyan, C.P. Hauri, R. Ischebeck, B. Monoszlai, L. Patthey, C. Pradervand, M. Radovic, L. Rivkin, V. Schlott, A.G. Stepanov
    PSI, Villigen PSI, Switzerland
  • I. Gorgisyan, C.P. Hauri, L. Rivkin
    EPFL, Lausanne, Switzerland
  • R. Ivanov, P. Peier
    DESY, Hamburg, Germany
  • J. Liu
    XFEL. EU, Hamburg, Germany
  • B. Monoszlai
    University of Pecs, Pécs, Hungary
  • K. Ogawa, T. Togashi, M. Yabashi
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • S. Owada
    JASRI/RIKEN, Hyogo, Japan
  The accurate, non-destructive measurements of FEL pulse length and arrival time relative to an experimental laser are necessary for operators and users alike. The FEL operators can get a better understanding of their machine and the optics of an FEL by examining the pulse length changes of the photons coming to the user stations, and the users can use the arrival time and pulse length information to better understand their data. PSI has created the pulse arrival and length monitor (PALM) based on the THz-streak camera concept for measurement at x-ray FELs, meant to be used at the upcoming SwissFEL facility. The first results from the experimental beamtime at SACLA will be presented, showcasing the accuracy and reliability of the device. Further plans for improvement and eventual integration into SwissFEL will also be presented.  
slides icon Slides THA01 [5.798 MB]  
THP082 Measurements of Compressed Bunch Temporal Profile using Electro-Optic Monitor at SITF 922
  • Ye. Ivanisenko, V. Schlott
    PSI, Villigen PSI, Switzerland
  • P. Peier
    DESY, Hamburg, Germany
  Funding: The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n.°290605 (PSI-FELLOW/COFUND)
The SwissFEL Injector Test Facility (SITF) is an electron linear accelerator with a single bunch compression stage at Paul Scherrer Institute (PSI) in Switzerland. Electro-optic monitors (EOMs) are available for bunch temporal profile measurements before and after the bunch compressor. The profile reconstruction is based upon spectral decoding technique. This diagnostic method is non-invasive, compact and cost-effective. It does not have high resolution and wide dynamic range of an RF transverse deflecting structure (TDS), but it is free of transverse beam size influence, what makes it a perfect tool for fast compression tuning. We present results of EOM and TDS measurements with down to 150 fs long bunches after the compression stage at SITF.
THP083 Coherent Radiation Diagnostics for Longitudinal Bunch Characterization at European XFEL 925
  • P. Peier, H. Dinter, C. Gerth
    DESY, Hamburg, Germany
  European XFEL comprises a 17.5 GeV linear accelerator for the generation of hard X-rays. Electron bunches from 20 pC to 1 nC will be produced with a length of a few ps in the RF gun and compressed by three orders of magnitude in three bunch compressor (BC) stages. European XFEL is designed to operate at 10 Hz delivering bunch trains with up to 2700 bunches separated by 222 ns. The high intra-bunch train repetition rate offers the unique possibility of stabilizing the machine with an intra-bunch train feedback, which puts in turn very high demand on fast longitudinal diagnostics. Two different systems will be installed in several positions of the machine. Five bunch compression monitors (BCM) will monitor the compression factor of each BC stage and used for intra-bunch train feedbacks. A THz spectrometer will be used to measure parasitically the longitudinal bunch profile after the energy collimator at 17.5 GeV beam energy. We will present concepts for fast longitudinal diagnostic for European XFEL based on coherent radiation, newest developments for high repetition rate measurements and simulations for the feedback capability of the system.  
Compact Synchronization of Optical Lasers to the Accelerator RF based on MTCA.4  
  • C. Gerth, Ł. Butkowski, M. Felber, U. Mavrič, P. Peier, H. Schlarb, B. Steffen
    DESY, Hamburg, Germany
  • E. Janas
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • T. Kozak, P. Prędki, K.P. Przygoda
    TUL-DMCS, Łódź, Poland
  X-ray free-electron laser facilities utilize a variety of optical short-pulse lasers to fully exploit the femtosecond time structure of the electron bunches and photon pulses. For temporal overlap, a precision synchronization of the optical lasers to the radio-frequency (RF) system of the FEL accelerator is required. A compact scheme for laser to external RF synchronization has been developed based on a digital controller implemented in MTCA.4 technology. An RF section is employed for the generation of electrical signals from the laser pulses. Further processing of the RF signals and phase locking to the reference is realized with commercially available MTCA.4 compliant modules. In this paper, we present a performance evaluation of the newly designed RF section, which consists of three printed circuit boards, as well as results from the synchronization of an Yb-fiber (1030 nm) and Er-fiber (1550 nm) laser to an RF reference source.