Author: Cullinan, F.J.
Paper Title Page
MOPC27 Cavity Beam Position Monitor System for ATF2 120
  • S.T. Boogert
    Royal Holloway, University of London, Surrey, United Kingdom
  • S.T. Boogert, F.J. Cullinan, Y.I. Kim, A. Lyapin, J. Snuverink
    JAI, Egham, Surrey, United Kingdom
  • T. Tauchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  • G.R. White
    SLAC, Menlo Park, California, USA
  The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 38 C- and S- band resonant cavity beam position monitors (CBPM) with associated mixer electronics and digitizers. The current status of the BPM system is described, including a study of the CBPM performance over a three week period, including systematic effects such as charge, bunch length and beam offset dependence. The BPM system is routinely used for beam based alignment, wakefield kick measurements and dispersion measurements, the operational experience and example measurements are also reported.  
TUPC19 First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam 411
  • F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler
    JAI, Egham, Surrey, United Kingdom
  • W. Farabolini, T. Lefèvre, L. Søby, M. Wendt
    CERN, Geneva, Switzerland
  Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.  
TUPC20 Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam 415
  • J.R. Towler, T. Lefèvre, L. Søby, M. Wendt
    CERN, Geneva, Switzerland
  • S.T. Boogert, F.J. Cullinan, A. Lyapin
    JAI, Egham, Surrey, United Kingdom
  The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.  
CBPM Waveform Deconvolution  
  • F.J. Cullinan
    JAI, Egham, Surrey, United Kingdom
  Francis presented simulations on the deconvolution of the cavity BPM response to a single bunch from signals obtained for a bunch train stimulus, based on the CTF3 beam parameters. In this case the bunch spacing is always short compared to the decay time τ of the BPM resonator. He tried to resolve individual bunches by the deconvolution method. Applying a random position jitter along the bunch train, he compared a simple downconversion procedure and a combination of downconversion and deconvolution to the original beam position. The DDC/deconvolution method seems to better resolve the beam position along the bunch train. He finally presented his method on measured ATF2 data.  
slides icon Slides FRWAJ5 [0.217 MB]