Author: Keil, B.
Paper Title Page
MOBL1 Instrumentation and Results from the SwissFEL Injector Test Facility 12
  • R. Ischebeck, V.R. Arsov, S. Bettoni, B. Beutner, M.M. Dehler, A. Falone, F. Frei, I. Gorgisyan, Ye. Ivanisenko, P.N. Juranic, B. Keil, F. Löhl, G.L. Orlandi, M. Pedrozzi, P. Pollet, E. Prat, T. Schietinger, V. Schlott, B. Smit
    PSI, Villigen PSI, Switzerland
  • P. Peier
    DESY, Hamburg, Germany
  The SwissFEL Injector Test Facility (SITF) has been equipped with numerous prototype diagnostics (BPMs, screen monitors, wire scanners, optical synchrotron radiation monitor, compression (THz) monitor, bunch arrival time monitor, EO spectral decoding monitor, charge and loss monitor) specifically designed for the low charge SwissFEL operation modes. The design of the diagnostics systems and recent measurement results will be presented.  
slides icon Slides MOBL1 [35.165 MB]  
TUPC25 Design of the SwissFEL BPM System 427
  • B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, F. Marcellini, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
    PSI, Villigen PSI, Switzerland
  SwissFEL is a Free Electron Laser (FEL) facility being constructed at PSI, based on a 5.8GeV normally conducting main linac. A photocathode gun will generate two bunches with 28ns spacing at 100Hz repetition rate, with a nominal charge range of 10-200pC. A fast beam distribution kicker will allow to distribute one bunch to a soft X-ray undulator line and the other bunch to a 0.1nm hard X-ray undulator line. The SwissFEL electron beam position monitor (BPM) system will employ three different types of dual-resonator cavity BPMs, since the accelerator has three different beam pipe apertures. In the injector and main linac (38mm and 16mm aperture), 3.3GHz cavity BPMs will be used, where a low Q of ~40 was chosen to minimize crosstalk of the two bunches*. In the undulators that just have single bunches and 8mm BPM aperture, a higher Q will be chosen. This paper reports on the development status of the SwissFEL BPM system. Synergies as well as differences to the E-XFEL BPM system** will also be highlighted.
* F. Marcellini et al., "Design of Cavity BPM Pickups For SwissFEL", Proc. IBIC'12, Tsukuba, Japan, 2012.
** B. Keil et al., "The European XFEL BPM System", Proc. IPAC'10, Kyoto, Japan, 2010.
poster icon Poster TUPC25 [1.074 MB]  
WEPC21 Design and Beam Test Results of Button BPMs for the European XFEL 723
  • D.M. Treyer, R. Baldinger, R. Ditter, B. Keil, W. Koprek, G. Marinkovic, M. Roggli
    PSI, Villigen PSI, Switzerland
  • D. Lipka, D. Nölle, S. Vilcins
    DESY, Hamburg, Germany
  Funding: Swiss State Secretariat for Education, Research and Innovation
The European X-ray Free Electron Laser (E-XFEL) will use a total ~300 button BPMs along the whole accelerator, as well as 160 cavity BPMs. The pickups for the button BPMs have been designed by DESY, whereas the electronics has been developed by PSI. This paper gives an overview of the button BPM system, with focus on the RF front end electronics, signal processing, and overall system performance. Measurement results achieved with prototypes installed at FLASH/DESY and at the SwissFEL Injector Test Facility (SITF) are presented. The position noise obtained with button pickups in a 40.5 mm aperture beam pipe is as low as ~11 um at 20 pC bunch charge.
poster icon Poster WEPC21 [1.595 MB]  
Cavity BPM Activities at PSI  
  • B. Keil
    PSI, Villigen PSI, Switzerland
  Boris reported on cavity BPM activities at PSI for various projects: Read-out electronics for FLASH and XFEL, and an entire cavity BPM system for the SwissFEL. He compared the requirements of the BPMs in the different areas of the accelerator, and presented the anticipated cavity BPM pickup and read-out solutions. Boris also showed the results from the prototype R&D at the SwissFEL Injector Test Facility, which included a different concept, with a direct analog downconversion to baseband, and a novel technique of ADC clock phase feedback to align ADC samples to the peak on the signal waveform. The resolution of the different prototype BPMs, achieved during the beam tests, range within a few 100nm, far better than the requirement. A very interesting side aspect mentioned by Boris, was the investigation of UHV coaxial feedthroughs for high frequencies. As everyone observes, the known niche companies increased their prices to the extreme, forcing the community to search for alternatives. Boris found a Swiss manufacturer, who now provides custom feedthroughs with acceptable UHV and RF properties (return loss >30dB@3GHz) at moderated to low costs. Very interesting!  
slides icon Slides FRWMJ6 [2.044 MB]