MOCB —  Contributed Talk in Monday-B   (01-Oct-12   10:20—12:00)
Beam Instrumentation of SuperKEKB Rings
  • H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
    KEK, Ibaraki, Japan
  • G. Bonvicini
    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.  
A Generic BPM Electronics Platform for European XFEL, SwissFEL and SLS
  • B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, G. Marinkovic, M. Roggli, M. Stadler, D.M. Treyer
    PSI, Villigen, Switzerland
  Funding: Work supported by Swiss State Secretariat for Education and Research SER
PSI is currently developing the 2nd generation of a generic modular electronics platform for linac and storage ring BPMs and other beam diagnostics systems. The first platform, developed in 2004 and based on a generic digital back-end with Xilinx Virtex 2Pro FPGAs, is currently used at PSI for proton accelerator BPMs, resonant stripline BPMs at the SwissFEL test injector facility, and a number of other diagnostics and detector systems. The 2nd platform will be employed e.g. for European XFEL BPMs, a new SLS BPM system, and the SwissFEL BPM system. This paper gives an overview of the architecture, features and applications of the new platform, including interfaces to control, timing and feedback systems. Differences and synergies of the different BPM and non-BPM applications will be discussed.
Modelling and Performance Evaluation of DCCTs in SSRF
  • Z.C. Chen, Y.B. Leng, Y. Xiong, W.M. Zhou
    SSRF, Shanghai, People's Republic of China
  Direct Current Current Transformer (DCCT) is the most commonly used high precision current monitor in modern particle accelerators including Shanghai Synchrotron Radiation Facility (SSRF). Three types of noise have been observed in the output signal of the DCCT in the storage ring of SSRF: power line noise, beam current related narrow band noise and random square wave noise from nowhere. This article will discuss the noise removal algorithms in SSRF and the performance of the DCCTs afterwards.  
Vertical Emittance Measurements using a Vertical Undulator
  • K.P. Wootton, R.P. Rassool, G. Taylor
    The University of Melbourne, Melbourne, Australia
  • M.J. Boland, B.C.C. Cowie, R.T. Dowd
    ASCo, Clayton, Victoria, Australia
  • Y. Papaphilippou
    CERN, Geneva, Switzerland
  With vertical dimensions of several microns, direct measurement of beam size is approaching diffraction limits of visible light and hard x-ray emittance diagnostics. We report on the development of a new vertical electron beam size measurement and monitoring technique which utilizes a vertical undulator. An APPLE-II type undulator was phased to produce a horizontal magnetic field, deflecting the electron beam in the vertical plane. The measured ratios of undulator spectral peak heights are evaluated by fitting to simulations of the apparatus. Vertical electron beam emittances of several picometres have been observed at the Australian Synchrotron storage ring. With this apparatus immediately available at most existing electron and positron storage rings, we find this to be an appropriate and novel vertical emittance diagnostic.