Keyword: sextupole
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MOPA30 Application of EMMA BPMs to the ALICE Energy Recovery Linac pick-up, FEL, EPICS, linac 117
 
  • A. Kalinin, D. Angal-Kalinin, F. Jackson, J.K. Jones, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The ALICE Energy Recovery Linac arc button pickups have been recently equipped with EMMA BPM electronics*. These bunch-by-bunch EPICS VME BPMs give information about charge and position, and its jitter, allowing estimates of the beam energy jitter in ALICE in different modes of operation. A Mathematica program is designed to monitor statistically individual bunches (spacing 61.54ns) as well the train as a whole (up to 1625 bunches), allowing the study of jitter and position stability of the beam through the arc. The ALICE arc has been designed to be isochronous, with the bunch compression achieved through a separate dedicated bunch compressor chicane. The arc incorporates two sextupoles for correcting non-linear longitudinal matrix terms and experimental evidence suggests that the off-centred beam in the sextupoles breaks the linear isochronicity. We present some beam measurement results collected in 2012 using these BPMs.
*A. Kalinin et al, MOPPR061, IPAC12
 
 
TUPA37 FPGA Based Fast Orbit Feedback System for the Australian Synchrotron feedback, FPGA, vacuum, fibre-optics 437
 
  • Y.E. Tan, T.D. Cornall, S.A. Griffiths, S. Murphy, E. Vettoor
    ASCo, Clayton, Victoria, Australia
 
  An initial design for a Fast Global Orbit Feedback System based on FPGAs has been proposed for the Australian Synchrotron Light Source (ASLS). The design uses a central processor (Xilinx Virtex 6) for all the computations and fast optical connections to distribute the computed data to corrector magnet power supplies. The network topology consists of two fibre optic rings. The first ring is used by the Libera Electron's to aggregate the beam position data at 10 kHz using Instrumentation Technologies' Grouping algorithm. The second ring is used to transmit the computed data. The cycle frequency of the feedback is 10 kHz with a targeted total latency of under 350 us. We shall give an overview of the design goals and discuss the merits of the current implementation. We shall also present the measured bandwidth of the stainless steel vacuum chamber and test results from initial prototyping work.