A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z    

Dehler, M.

Paper Title Page
MOPCH042 Progress in the Design of a Two-Frequency RF Cavity for an Ultra-Low Emittance Pre-Accelerated Beam 133
 
  • J.-Y. Raguin, A. Anghel, R.J. Bakker, M. Dehler, R. Ganter, C. Gough, S. Ivkovic, E. Kirk, F. Le Pimpec, S.C. Leemann, K.L. Li, M. Paraliev, M. Pedrozzi, L. Rivkin, V. Schlott, A.F. Wrulich
    PSI, Villigen
 
  Today most of the X-rays Free-Electron Laser projects are based on state of the art RF guns, which aim at a normalized electron beam emittance close to 1 mm$·$mrad. In this paper we report on the progress made at PSI towards a hybrid DC + RF Low Emittance Gun (LEG) capable of producing a beam with an emittance below 0.1 mm.mrad. To reduce the intrinsic thermal emittance at the LEG cathode the electrons are extracted from nano-structured field-emitters. A gun test facility is under construction wherein after emission the beam is accelerated up to 500 keV in a diode before being injected and accelerated in a two-frequency 1.5-cell RF cavity. The fast acceleration in the diode configuration allows to minimize the emittance dilution due to the strong space charge forces. The two-frequency RF structure is optimized to limit the emittance blow-up due to the non-linearity of the RF field.  
THPCH096 Intra Bunch Train Feedback System for the European X-FEL 3017
 
  • V. Schlott, M. Dehler, B. Keil, R. Kramert, A. Lounine, G. Marinkovic, P. Pollet, M. Roggli, T. Schilcher, P. Spuhler, D.M. Treyer
    PSI, Villigen
 
  After joining the preparatory phase of the European X-FEL project, the Paul Scherrer Institut (PSI) agreed in taking over responsibility for electron beam stabilization by developing a fast intra bunch train feedback (IBFB) system, which will be tested in its prototype version at the VUV-FEL facility at DESY. The IBFB will make use of the long bunch trains provided by the superconducting drive accelerators of the VUV- as well as the European X-FEL allowing to damp beam motions in a frequency range of a few kHz up to several hundreds of kHz applying modern control algorithms in a feedback loop. The FPGA-based, digital data processing and the low latency time (preferably < 200 ns) permit the elimination of long range (from bunch train to bunch train) and ultra fast (bunch by bunch) repetitive beam movements by adaptive feed forwards. In this paper, we will introduce the IBFB design concept and report on first test measurements with newly designed stripline beam position monitors for the VUV-FEL.  
THPCH098 FPGA-based Longitudinal Bunch-by-bunch Feedback System for TLS 3023
 
  • C.H. Kuo, J. Chen, P.J. Chou, K.-T. Hsu, S.Y. Hsu, K.H. Hu, W.K. Lau, D. Lee, C.-J. Wang, M.-H. Wang, M.-S. Yeh
    NSRRC, Hsinchu
  • M. Dehler
    PSI, Villigen
  • K. Kobayashi, T. Nakamura
    JASRI/SPring-8, Hyogo-ken
 
  A FPGA Based Longitudinal Bunch-by-Bunch Feedback System for TLS is commissioning recently to suppress strong longitudinal oscillation. The system consists of pickup, Bunch oscillation detector, FPGA based feedback processor borrow form the design of Spring8. Modulator converts the correction signal to the carrier frequency and longitudinal kicker which was re-designed form SLS' and working at 1374 MHz. The feedback processor is based upon latest generation FPGA feedback processor to process bunch signals. The memory capture is up to 250 msec bunch oscillation signal. The software and hardware design are also included for system diagnostic and support various beam physics study. Preliminary commission result will be summaried in this report.