A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Zaugg, T.

Paper Title Page
MOPAS050 Active Damping of the e-p Instability at the LANL PSR 548
 
  • R. C. McCrady, R. J. Macek, S. B. Walbridge, T. Zaugg
    LANL, Los Alamos, New Mexico
  • S. Assadi, C. Deibele, S. Henderson, M. A. Plum
    ORNL, Oak Ridge, Tennessee
  • J. M. Byrd
    LBNL, Berkeley, California
  • S.-Y. Lee
    IUCF, Bloomington, Indiana
  • M. T.F. Pivi
    SLAC, Menlo Park, California
 
  Funding: This work was supported by the United States Department of Energy under contracts DE-AC52-06NA25396 and W-7405-ENG-36.

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos National Laboratory Proton Storage Ring (PSR). This system was able to improve the instability threshold by approximately 30% (as measured by the change in RF buncher voltage at instability threshold). Evidence obtained from these tests suggests that further improvement in performance is limited by beam leakage into the gap at lower RF buncher voltage and the onset of instability in the horizontal plane, which had no feedback. Here we describe the present system configuration, system optimization, results of several recent experimental tests, and results from studies of factors limiting its performance.

 
TUODAB02 Electron Cloud Generation and Trapping in a Quadrupole Magnet at the LANL PSR 828
 
  • R. J. Macek, J. E. Ledford, R. J. Macek
    TechSource, Santa Fe, New Mexico
  • M. J. Borden, A. A. Browman, R. C. McCrady, J. F. O'Hara, L. Rybarcyk, T. Spickermann, T. Zaugg
    LANL, Los Alamos, New Mexico
  • M. T.F. Pivi
    SLAC, Menlo Park, California
 
  Funding: Work supported by DOE SBIR Grant No. DE-FG02-04ER84105 and CRADA No. LA05C10535 between TechSource, Inc. and the Los Alamos National Laboratory.

Recent beam physics studies on the two-stream e-p instability at LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Experimental results will be presented on various characteristics of electron cloud obtain from experiments using this diagnostic and compared with simulations. Results include data on flux and energy spectra of electrons striking the vacuum chamber, the line density and lifetime of electrons trapped in the quadrupole after the beam has been extracted as well as evidence regarding electrons ejected from the magnet during passage of the proton beam.

 
slides icon Slides  
WEXC01 Experimental Tests of a Prototype System for Active Damping of the E-P Instability at the LANL PSR 1991
 
  • C. Deibele, S. Assadi, V. V. Danilov, S. Henderson, M. A. Plum, A. K. Polisetti
    ORNL, Oak Ridge, Tennessee
  • J. M. Byrd
    LBNL, Berkeley, California
  • J. D. Gilpatrick, R. C. McCrady, J. F. Power, T. Zaugg
    LANL, Los Alamos, New Mexico
  • S.-Y. Lee
    IUCF, Bloomington, Indiana
  • M. T.F. Pivi
    SLAC, Menlo Park, California
  • M. J. Schulte, Z. P. Xie
    UW-Madison, Madison, Wisconsin
 
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract DE-AC05-00OR22725.

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos Proton Storage Ring (PSR). This talk describes the system configuration, results of several experimental tests and studies of system optimization along with studies of the factors limiting its performance.

 
slides icon Slides