Author: Cerniglia, P.
Paper Title Page
MOP267 Fast BPM Data Distribution for Global Orbit Feedback Using Commercial Gigabit Ethernet Technology 606
 
  • R.L. Hulsart, P. Cerniglia, R.J. Michnoff, M.G. Minty
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In order to correct beam perturbations in RHIC around 10Hz, a new fast data distribution network was required to deliver BPM position data at rates several orders of magnitude above the capability of the existing system. The urgency of the project limited the amount of custom hardware that could be developed, which dictated the use of as much commercially available equipment as possible. The selected architecture uses a custom hardware interface to the existing RHIC BPM electronics together with commercially available Gigabit Ethernet switches to distribute position data to devices located around the collider ring. Using the minimum Ethernet packet size and a field programmable gate array (FPGA) based state machine logic instead of a software based driver, real-time and deterministic data delivery is possible using Ethernet. The method of adapting this protocol for low latency data delivery, bench testing of Ethernet hardware, and the logic to construct Ethernet packets using FPGA hardware will be discussed.
 
 
MOP268 RHIC 10 Hz Global Orbit Feedback System 609
 
  • R.J. Michnoff, L. Arnold, C. Carboni, P. Cerniglia, A.J. Curcio, L. DeSanto, C. Folz, C. Ho, L.T. Hoff, R.L. Hulsart, R. Karl, C. Liu, Y. Luo, W.W. MacKay, G.J. Mahler, W. Meng, K. Mernick, M.G. Minty, C. Montag, R.H. Olsen, J. Piacentino, P. Popken, R. Przybylinski, V. Ptitsyn, J. Ritter, R.F. Schoenfeld, P. Thieberger, J.E. Tuozzolo, A. Weston, J. White, P. Ziminski, P. Zimmerman
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Vibrations of the cryogenic triplet magnets at the Relativistic Heavy Ion Collider (RHIC) are suspected to be causing the beam perturbations observed at frequencies around 10 Hz. Several solutions to counteract the effect have been considered in the past, including reinforcing the magnet base support assembly, a mechanical servo feedback system, and a local beam feedback system at each of the two experimental areas. However, implementation of the mechanical solutions would be expensive, and the local feedback system was insufficient since perturbation amplitudes outside the experimental areas were still problematic. A global 10 Hz orbit feedback system is currently under development at RHIC consisting of 36 beam position monitors (BPMs) and 12 small dedicated dipole corrector magnets in each of the two counter-rotating rings. A subset of the system consisting of 8 BPMs and 4 corrector magnets in each ring was installed and successfully tested during the RHIC 2010 run; and the complete system is being installed for the 2011 run. A description of the overall system architecture and results with beam will be discussed.