Author: Neupert, H.
Paper Title Page
WEPEA014 Recent Electron Cloud Studies in the SPS 2525
  • G. Iadarola, H. Bartosik, M. Driss Mensi, H. Neupert, G. Rumolo, M. Taborelli
    CERN, Geneva, Switzerland
  • G. Iadarola
    Naples University Federico II, Science and Technology Pole, Napoli, Italy
  It is important to qualify the present status of the SPS with respect to the electron cloud before the Long Shutdown of the CERN accelerator complex, which will take place in 2013-2014. Therefore several electron cloud studies were performed during the 2012 run in order to get a full characterization of the behavior of the SPS with the LHC-type beams with 25 ns bunch spacing, which can be very sensitive to electron cloud effects. The collected information should allow to understand up to which extent this long period without beam operation - and the related interventions on the machine - will degrade the present conditioning state of the SPS, which has been achieved by “scrubbing” over several years. Several measurements with different beam conditions have been collected also on the electron cloud detectors installed in the machine. These results, in combination with detailed simulation studies, will provide the basis for defining strategies of electron cloud mitigation as required for the production of future high intensity and high brightness beams within the LHC Injectors Upgrade (LIU) project.  
THPFI093 Device and Technique for In-situ Coating of the RHIC Cold Bore Vacuum Tubes with Thick OFHC 3508
  • A. Hershcovitch, M. Blaskiewicz, J.M. Brennan, W. Fischer, C.J. Liaw, W. Meng, R.J. Todd
    BNL, Upton, Long Island, New York, USA
  • A.X. Custer, M.Y. Erickson, N.Z. Jamshidi, H.J. Poole
    PVI, Oxnard, USA
  • J.M. Jimenez, H. Neupert, M. Taborelli, C. Yin Vallgren
    CERN, Geneva, Switzerland
  • N. Sochugov
    Institute of High Current Electronics, Tomsk, Russia
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
To mitigate electron clouds & unacceptable ohmic heating problems in RHIC, we developed a robotic plasma deposition technique & device to in-situ coat the RHIC 316LN SS cold bore tubes based on mobile mole mounted magnetrons for OFHC deposition. Scrubbed Cu has low SEY and suppress electron cloud formation. Room temperature RF resistivity measurement of Cu coated SS RHIC tube samples indicate that 10 μm of Cu coating has conductivity close to copper tubing. A 50 cm long copper cathode magnetron, mounted on a carriage with spring loaded wheels, was successfully operated, traversed magnet interconnect bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. To maximize cathode lifetime, Cu cathode thickness was maximized its gap to vacuum tube minimized; movable magnet package is used. Novel cabling and vacuum-atmosphere interface system is being developed. Deposition experiments show no indentation in or damage to coating after wheels roll over coated areas; i.e. train like assembly option is a viable for in-situ RHIC coating. Details of experimental setup & coating of full-scale magnet tube sandwiched between bellows will be presented.