Keyword: kicker
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MOCB01 Beam Instrumentation for the SuperKEKB Rings detector, feedback, radiation, damping 6
 
  • H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
    KEK, Ibaraki, Japan
  • G. Bonvicini, H. Farhat, R.S. Gillard
    Wayne State University, USA
  • G.S. Varner
    University of Hawaii, Honolulu, HI, USA
 
  The electron-positron collider KEKB B-factory is currently being upgraded to SuperKEKB. The design luminosity of 8 x 1035 /cm2/s will be achieved using beams with low emittance of several nm and doubling beam currents to 2.6 A in the electron ring (HER) and 3.6 A in the positron ring (LER). A beam position monitor (BPM) system of HER and LER will be equipped with super-heterodyne detectors, turn by turn log ratio detectors with fast gates to measure optics parameters during collision operation and detectors of BPMs near the collision point (IP) for orbit feedback to maintain stable collision. New X-ray beam profile monitors based on the coded aperture method will be installed aiming at bunch by bunch measurement of the beam profile. A large angle beamstrahlung monitor detecting polarization of the synchrotron radiation generated by beam-beam interaction will be installed near IP to obtain information about the beam-beam geometry. The bunch by bunch feedback system will be upgraded using low noise frontend electronics and new 12 bits iGp digital filters. An overview of beam instrumentation of SuperKEKB rings will be given in this paper.  
slides icon Slides MOCB01 [8.073 MB]  
 
MOPA01 Design Study of the Striplines for the Extraction Kicker of the CLIC Damping Rings impedance, coupling, simulation, damping 47
 
  • C. Belver-Aguilar, A. Faus-Golfe
    IFIC, Valencia, Spain
  • M.J. Barnes
    CERN, Geneva, Switzerland
  • F. Toral
    CIEMAT, Madrid, Spain
 
  Pre-Damping Rings (PDRs) and Damping Rings (DRs) are needed to reduce the beam emittance and, therefore, to achieve the luminosity requirements for the CLIC main linac. Several stripline kicker systems will be used to inject and extract the beam from the PDRs and DRs. Results of initial studies of the stripline cross-section and the beam coupling impedance, for a non-tapered beam pipe, have previously been reported. In this paper, we present the analysis to study the final choice of the cross-section design, based on impedance matching and field inhomogeneity requirements, the power reflected in the transition between an electrode and the input coaxial feedthrough, and the predicted beam coupling impedance. Mechanical tolerances for the stripline manufacturing process are presently being studied. The striplines are planned to be prototyped by December 2012.  
 
MOPA35 Design Status of the European X-FEL Tranverse Intra Bunch Train Feedback undulator, feedback, FPGA, cavity 133
 
  • B. Keil, R. Baldinger, C.D. Beard, M.M. Dehler, W. Koprek, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
    PSI, Villigen PSI, Switzerland
  • V. Balandin, W. Decking, N. Golubeva
    DESY, Hamburg, Germany
 
  Funding: Work supported by Swiss State Secretariat for Education and Research SER
The European X-Ray Free Electron Laser (E-XFEL) will have a fast transverse intra-bunch train feedback (IBFB) system to stabilize the beam position in the SASE undulators. E-XFEL bunch trains consist of up to 2700 bunches with a minimum bunch spacing of 222ns and typ. 10Hz train repetition rate. The IBFB will measure the positions of each bunch in the bunch train, and apply intra-train feedback corrections with fast kickers, in addition to a feed-forward correction for reproducible trajectory perturbations. By achieving a feedback loop latency in the order of one microsecond, the IBFB will allow the beam position to converge quickly to the nominal orbit as required for stable SASE operation. The latest conceptual design of the IBFB and the status of IBFB components will be presented.
 
 
MOPA47 Planar Transmission Line BPM for Horizontal Aperture Chicane for XFEL pick-up, simulation, electron, electronics 168
 
  • A. Angelovski, R. Jakoby, A. Penirschke
    TU Darmstadt, Darmstadt, Germany
  • C. Gerth, U. Mavrič, C. Sydlo
    DESY, Hamburg, Germany
 
  In order to obtain ultra-short bunches in the Free Electron Laser FLASH at DESY, the electron beam is compressed in magnetic chicanes. Precise knowledge of the beam position in the chicane is of great significance for the longitudinal dynamics control. In the current implementation cylindrical pickup-striplines mounted perpendicularly to the beam are used as a Beam Position Monitor (BPM)(*). One can determine the horizontal beam position by measuring the phase difference of the beam induced signal at opposite ends of a pickup. Due to the different electrical and mechanical requirements for the European XFEL a new BPM has to be developed. In this paper, we present the design and analysis of a planar transmission line structure which is planned to be used as a BPM in the European XFEL. The planar design of the pickups can provide for proper impedance match to the subsequent electronics as well as sufficient mechanical stability along the aperture when using alumina substrates. A scaled non-hermetic prototype of the BPM is built and characterized by scattering parameters. The measurement results are compared to simulations obtained by CST STUDIO SUITE®.
(*) K. Hacker at el, Proceedings of DIPAC 2007, Venice, Italy 2007, p.108
 
 
TUTA02 BPM Electrode and High Power Feedthrough - Special Topics in Wideband Feedthrough simulation, vacuum, impedance, linac 297
 
  • M. Tobiyama
    KEK, Ibaraki, Japan
 
  Since most of the beam in accelerator runs in the vacuum chamber made of metal, it is needed to have 'feedthrough' to get or to put the RF signal from or to beam. For example, we can get the beam signal by using button-type electrode which have electrical isolation material to seal the vacuum. Now, many types of vacuum feedthrough with coaxial structure are available commercially. Nevertheless, it is meaningful to understand the design principle of the feedthough needed for the beam instrumentation, especially for short bunch length, high beam current machine. I will show the design method of the feedthrough such as BPM electrodes or high power feedthroughs using 3D EM-codes such as HFSS or GdfidL based on several examples developed for SuperKEKB accelerators.  
slides icon Slides TUTA02 [6.806 MB]  
 
TUPA02 Modernized of the Booster Synchrotron Diagnostics in the Taiwan Light Source booster, synchrotron, extraction, radiation 329
 
  • C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu
    NSRRC, Hsinchu, Taiwan
 
  Taiwan Light Source is an 1.5 GeV synchrotron based light source which dedicated almost 20 year ago. During several major and minor upgrades, the TLS operate in top-up mode. To provide a better operation of the injector for the TLS, several minor upgrade in diagnostics are proceed recently. Efforts of these upgrades and modifications will summary in this report.  
 
TUPA10 Optical-Fiber Beam Loss Monitor for the KEK Photon Factory injection, vacuum, electron, storage-ring 351
 
  • T. Obina, Y. Yano
    KEK, Ibaraki, Japan
 
  Beam loss monitor system using optical fibers has been developed to determine the loss point of the injected beam at the KEK Photon Factory (PF) electron storage ring. Large-core optical fiber was installed along the vacuum chamber of the storage ring, of which circumference is about 187m. In order to cover the whole location, total 10 optical fibers with the length of 30 m is used. Both ends of the fiber has been fed out of the radiation shield of the ring. The Cherenkov light produced by the electron which is not captured in the ring, is detected by a photomultiplier tube (PMT) attached on the upstream side of the fiber. Rise-time of the PMT of 5 ns is fast enough to determine the location of the beam loss point. In the KEK-PF, two kinds of injection system, kicker magnets and a pulsed sextupole magnet (PSM), has been used for the routine operation. In this paper, details of the loss monitor system are reported and the difference of the two injection system will be discussed.  
 
TUPA35 Digital Longitudinal Bunch-by-bunch Feedback System for the HLS II feedback, cavity, impedance, storage-ring 434
 
  • W.B. Li, P. Lu, B.G. Sun, F.F. Wu, W. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  In order to suppress the longitudinal coupled bunch instabilities, a digital longitudinal bunch-by-bunch feedback system will be developed in the upgrade project of Hefei Light Source (HLS II). The longitudinal feedback system consists of a pickup BPM, a front-end signal processor unit to detect the phase errors of all electron bunches, an iGp signal processor to calculate correction signals of those bunches, two RF power amplifiers, and a longitudinal kicker to supply proper correction energy kicks to individual bunches. A new waveguide overloaded cavity longitudinal feedback kicker has been designed with broadband and high shunt impedance. In this paper, we describe an overview of the new longitudinal feedback system.