Author: Harkay, K.C.
Paper Title Page
TUPC030 Recommendation for Mitigations of the Electron Cloud Instability in the ILC 1063
 
  • M.T.F. Pivi, L. Wang
    SLAC, Menlo Park, California, USA
  • L.E. Boon, K.C. Harkay
    ANL, Argonne, USA
  • J.A. Crittenden, G. Dugan, M.A. Palmer
    CLASSE, Ithaca, New York, USA
  • T. Demma, S. Guiducci
    INFN/LNF, Frascati (Roma), Italy
  • M.A. Furman
    LBNL, Berkeley, California, USA
  • K. Ohmi, K. Shibata, Y. Suetsugu, J. Urakawa
    KEK, Ibaraki, Japan
  • C. Yin Vallgren
    Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
 
  Funding: Work supported by the Director, Office of Science, High Energy Physics, U.S. DOE under Contract No. DE-AC02-76SF00515.
Electron cloud has been identified as one of the highest priority issues for the ILC Damping Rings (DR). A working group has evaluated the electron cloud effect and instability, and mitigation solutions for the electron cloud formation. Working group deliverables include recommendations for the baseline and alternate solutions for the electron cloud mitigation in various regions of the ILC Positron DR, which is presently assumed to be the 3.2km design. Detailed studies of a range of mitigation options including coatings, clearing electrodes, grooves and novel concepts, were carried out over the previous several years by nearly 50 researchers, and the results of the studies form the basis for the recommendation. The assessments of the benefits or risks associated with the various options were based on a systematic ranking scheme. The recommendations are the result of the working group discussions held at numerous meetings and during a dedicated workshop. The mitigation choices will be also presented in a more detailed report later in 2012. In addition, a number of items requiring further investigation were identified and studies will be carried out at CesrTA and other institutions.
 
 
WEPC141 Application of the SYNRAD3D Photon-Tracking Model to Shielded Pickup Measurements of Electron Cloud Buildup at CesrTA 2319
 
  • L.E. Boon
    Purdue University, West Lafayette, Indiana, USA
  • J.A. Crittenden, T. Ishibashi
    CLASSE, Ithaca, New York, USA
  • K.C. Harkay
    ANL, Argonne, USA
 
  Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
We present calculations of synchrotron radiation photon reflection in the vacuum chamber at the Cornell Electron Storage Ring Test Accelerator (CesrTA), applying them as input to the electron cloud buildup code ECLOUD to model time-resolved local measurements with shielded pickup detectors. The recently developed SYNRAD3D photon-tracking code employs a reflection model based on data from the Center for X-Ray Optics at LBNL. This study investigates the dependence of electron cloud buildup on the azimuthal position and kinetic energy distribution of photoelectron production on the vacuum chamber wall.
 
 
THPC186 Heat Load for the APS Superconducting Undulator 3332
 
  • L.E. Boon, A.F. Garfinkel
    Purdue University, West Lafayette, Indiana, USA
  • K.C. Harkay
    ANL, Argonne, USA
 
  Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Upgrade calls for the development and commissioning of a superconducting undulator (SCU) at the Advanced Photon Source (APS), a 7-GeV electron synchrotron. The first SCU will be installed in June 2012. Until then, simulations such as SYNRAD3D will be used to understand and reduce the heat load on the cryo-system from primary and secondary photons. Current calculations predict that primary photons will distribute 0.5W/m on the chamber walls of the cryostat. SYNRAD3D will be used to calculate the ratio of primary and secondary photons to calculate the heat load due to secondary photons. Previous simulations were of only one sector of the APS accelerator. Simulated here are multiple sectors, to include photons back scattered from downstream photon absorbers.