Author: Apsimon, R.
Paper Title Page
MOPME069 Multi-OTR System for Linear Colliders 637
  • J. Resta-López, A. Faus-Golfe
    IFIC, Valencia, Spain
  • J. Alabau-Gonzalvo, R. Apsimon, A. Latina
    CERN, Geneva, Switzerland
  We study the feasibility of using a multi-Optical Transition Radiation (mOTR) system for fast transverse emittance reconstruction and x-y coupling correction in the Ring to Main Linac (RTML) of the future linear colliders: ILC and CLIC. OTR monitors are mature and reliable diagnostic tools that could be very suitable for the setup and tuning of the machine in single-bunch mode. Here we study the requirements for a mOTR system adapted to the optical conditions and beam parameters of the RTML of both the ILC and CLIC.  
MOPWA057 Development of a High-resolution, Broad-band, Stripline Beam Position Monitoring System 804
  • G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry
    JAI, Oxford, United Kingdom
  • R. Apsimon, B. Constance
    CERN, Geneva, Switzerland
  • P. Burrows, C. Perry
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • J. Resta
    IFIC, Valencia, Spain
  A low-latency, sub-micron resolution stripline beam position monitoring system has been developed and tested with beam at the KEK Accelerator Test Facility, where it has been used as part of a feedback system for beam stabilisation. The fast analogue front-end signal processor is based on a single-stage down-mixer and is combined with an FPGA-based system for digitisation and feedback control. A resolution as low as 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The latest results of recent modifications to balance the input path lengths to the processor will be discussed. These modifications compensate for the inherent phase sensitivity of the processors, and hence improve the intrinsic resolution, without the need for offline correction. Modifications to the FPGA firmware will also be described, to allow for flexible operation with variable system-synchronous data acquisition at up to 400 MHz, with up to nine data channels of 13-bit width, and a nominal record length of 1 KS/channel/pulse (extensible to a total record length of 120 KS per pulse, for example, for use with long bunch trains or wide-band multi-turn measurements in storage rings).  
MOPWO024 Design of the CLIC Pre-Main Linac Collimation System 936
  • R. Apsimon, A. Latina, D. Schulte, J.A. Uythoven
    CERN, Geneva, Switzerland
  • J. Resta-López
    IFIC, Valencia, Spain
  A main beam collimation system, upstream of the main linac, is essential to protect the linac from particles in the beam halo. The proposed system consists of an energy collimation (EC) system just after the booster linac near the start of the Ring-to-Main Linac (RTML) transfer line and an EC and betatron collimation (BC) system at the end of the RTML, just before the main linac. The design requirements are presented and the cleaning efficiency of the proposed systems is analysed for different design choices.  
MOPWO025 Optics and Protection of the Injection and Extraction Regions of the CLIC Damping Rings 939
  • R. Apsimon, B. Balhan, M.J. Barnes, J. Borburgh, B. Goddard, Y. Papaphilippou, J.A. Uythoven
    CERN, Geneva, Switzerland
  The optics design of the injection and extraction regions for the CLIC damping rings is presented. The design defines the parameters for the kicker magnets and septa in these regions and has been optimised to minimise the length of the insertions within the parameter space of the system. Failure modes of the injection and extraction elements are identified and their severity assessed. Protection elements for the injection and extraction regions are optimised based on the conclusions of the failure mode analysis.  
WEPME053 Latest Performance Results from the FONT 5 Intra Train Beam Position Feedback System at ATF 3049
  • M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry
    JAI, Oxford, United Kingdom
  • R. Apsimon, B. Constance, A. Gerbershagen
    CERN, Geneva, Switzerland
  A prototype ultra-fast beam-based feedback system for deployment in single-pass beamlines, such as a future lepton collider (ILC or CLIC) or a free-electron laser, has been fabricated and is being tested in the extraction and final focus lines of the Accelerator Test Facility (ATF) at KEK. FONT5 is an intra-train feedback system for stabilising the beam orbit via different methods: a position and angle feedback correction in the extraction line or a vertical feedforward correction applied at the interaction point (IP) . Two systems comprise three stripline beam position monitors (BPMs) and two stripline kickers in the extraction line, two cavity BPMs and a stripline kicker at the IP, a custom FPGA-based digital processing board, custom kicker-drive amplifiers and low-latency analogue front-end BPM processors. Latest results from the experiment are presented. These include beam position correction in the extraction line, as well as preliminary results of beam correction at the IP.