IPAC2013 - List of Authors (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.

Paper

Title

Page

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.