Author: Branlard, J.
Paper Title Page
MOPAB044 X-Band TDS Project 184
 
  • B. Marchetti, R.W. Aßmann, B. Beutner, J. Branlard, F. Christie, R.T.P. D'Arcy, W. Decking, U. Dorda, J. Herrmann, M. Hoffmann, M. Hüning, O. Krebs, G. Kube, S. Lederer, F. Ludwig, F. Marutzky, D. Marx, J. Osterhoff, I. Peperkorn, S. Pfeiffer, F. Poblotzki, J. Rönsch-Schulenburg, J. Rothenburg, H. Schlarb, M. Scholz, S. Schreiber, M. Vogt, A. Wagner, T. Wilksen, K. Wittenburg
    DESY, Hamburg, Germany
  • M. Bopp, H.-H. Braun, P. Craievich, M. Pedrozzi, E. Prat, S. Reiche, K. Rolli, R. Zennaro
    PSI, Villigen PSI, Switzerland
  • N. Catalán Lasheras, A. Grudiev, G. McMonagle, W. Wuensch
    CERN, Geneva, Switzerland
 
  Based on the success of the X-Band Transverse Deflecting Structure (TDS) diagnostic at LCLS*, a collaboration between DESY, PSI and CERN has formed with the aim of developing and building an advanced modular X-Band TDS system. The designed TDS has the new feature of providing variable polarization of the deflecting field**. The possibility of changing the orientation of the streaking field of the TDS to an arbitrary azimuthal angle allows for 3D characterization of the phase space using tomographic methods***. Moreover the complete 6D characterization of the beam phase space is possible by combining this technique with quadrupole scans and a dipole spectrometer. As this new cavity design requires very high manufacturing precision to guarantee highest azimuthal symmetry of the structure to avoid the deterioration of the polarization of the streaking field, the high precision tuning-free assembly procedures developed at PSI for the SwissFEL C-band accelerating structures will be used for the manufacturing****. The high-power rf system is based on the CERN-based X-band test stands. We summarize in this work the status of the projects and its main technical parameters.
* C. Behrens et al. , Nat. Comm. 4762 (2014).
** A. Grudiev, CLIC-note-1067 (2016).
*** D. Marx et al., contribution to this conference proceedings.
**** U. Ellenberger et al., FEL 2013, TUPS017.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB044  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPVA058 Commissioning and Operation Experience of the 3.9 GHz System in the EXFEL Linac 999
 
  • C.G. Maiano, J. Branlard, M. Hüning, M. Omet, P. Pierini, E. Vogel
    DESY, Hamburg, Germany
  • A. Bosotti, R. Paparella, P. Pierini, D. Sertore
    INFN/LASA, Segrate (MI), Italy
 
  The European X-ray Free Electron Laser (EXFEL) injector linac hosts a 3.9~GHz module (AH1) for beam longitudinal phase space manipulation after the first acceleration stage, in order for the linac to deliver the high current beams with sufficiently low emittance for the production of 1 Angstrom FEL light to the experimental users. The module was technically commissioned in December 2015 and operated well above its nominal performances during the Injector Run from January to July 2016. Its operation has restarted in January 2017 with the startup of the whole facility, and the system met the design beam specifications after the bunch compression stages. A brief review of the commissioning and first operation experience of the RF system are presented here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA058  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPVA066 Limits for the Operation of the European XFEL 3.9 GHz System in CW Mode 1023
 
  • P. Pierini, A. Bosotti, R. Paparella, D. Sertore
    INFN/LASA, Segrate (MI), Italy
  • J. Branlard, D. Kostin, C.G. Maiano, W.-D. Möller, P. Pierini, D. Reschke, J.K. Sekutowicz, E. Vogel
    DESY, Hamburg, Germany
 
  Future upgrades of the European XFEL (EXFEL) facility may require driving the linac at higher duty factor, possibly extending to CW mode at reduced gradients. A preliminary analysis for the accelerator modules has been presented in the EXFEL TDR, but no precise assessment has been performed so far for the present 3.9 GHz system design. By making use of data collected during the commissioning and operation phase of the EXFEL injector system, we discuss here an estimate for the limits of CW operation of the present system and a plan for its possible experimental verification with existing available cavities and the EXFEL spare module.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA066  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THOAA3 Installation and First Commissioning of the LLRF System for the European XFEL 3638
 
  • J. Branlard, G. Ayvazyan, V. Ayvazyan, Ł. Butkowski, M. Fenner, M.K. Grecki, M. Hierholzer, M. Hoffmann, M. Killenberg, D. Kostin, D. Kühn, F. Ludwig, D.R. Makowski, U. Mavrič, M. Omet, S. Pfeiffer, H. Pryschelski, K.P. Przygoda, A.T. Rosner, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, B. Szczepanski, G. Varghese, H.C. Weddig, R. Wedel, M. Wiencek, B.Y. Yang
    DESY, Hamburg, Germany
  • W. Cichalewski, F. Makowski, A. Mielczarek, P. Perek
    TUL-DMCS, Łódź, Poland
  • K. Czuba, P.K. Jatczak, T.P. Leśniak, K. Oliwa, D. Sikora, M. Urbański, W. Wierba
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • A.S. Nawaz
    TUHH, Hamburg, Germany
 
  The installation phase of the European X-ray free laser electron laser (XFEL) is finished, leaving place for its commissioning phase. This contribution summarizes the low-level radio frequency (LLRF) installation steps, illustrated with examples of its challenges and how they were addressed. The commissioning phase is also presented, with a special emphasis on the effort placed into developing LLRF automation tools to support the commissioning of such a large scale accelerator. The first results of the LLRF commissioning of the XFEL injector and first RF stations in the main linac are also given.  
slides icon Slides THOAA3 [15.800 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOAA3  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPAB103 On-Line RF Amplitude and Phase Calibration 3957
 
  • M.K. Grecki, V. Ayvazyan, J. Branlard, M. Hoffmann, M. Omet, H. Schlarb, Ch. Schmidt
    DESY, Hamburg, Germany
 
  The accelerating RF field has crucial importance on the beam properties. It is not only used just to accelerate particles but also to shape the bunches at bunch compressors. It is really important to control and measure the field as seen by the beam while usually only indirect (not using the beam) field measurements are available*. Since they are affected by many contributions the measurements must be always calibrated to the beam. Usually this calibration is performed at special operating conditions that prevents normal operation of the accelerator. During normal operation the calibrations is assumed to not drift which is certainly not perfectly true and introduce some control errors. The paper shows how to extract the RF-beam calibration from RF signals during normal operating condition (when RF feed-back, beam loading compensation, learning feed-forward etc. are active). All the algorithms and computations were performed on signals recorded at FLASH accelerator but the main idea is general and can be used at other locations as well.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB103  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)