Author: Padamsee, H.
Paper Title Page
TUP096 Beam Pipe HOM Absorber for SRF Cavities 1012
 
  • R. Sah, A. Dudas, M.L. Neubauer
    Muons, Inc, Batavia, USA
  • G.H. Hoffstaetter, M. Liepe, H. Padamsee, V.D. Shemelin
    CLASSE, Ithaca, New York, USA
  • K. Ko, C.-K. Ng, L. Xiao
    SLAC, Menlo Park, California, USA
 
  Funding: Supported in part by DOE SBIR grant DE-SC0002733 and USDOE Contract No. DE-AC05-84-ER-40150.
Superconducting RF (SRF) systems typically contain resonances at unwanted frequencies, or higher order modes (HOM). For storage ring and linac applications, these higher modes must be damped by absorbing them in ferrite and other lossy ceramic materials. Typically, these absorbers are brazed to substrates that are often located in the drift tubes adjacent to the SRF cavity. These HOM absorbers must have broadband microwave loss characteristics and must be thermally and mechanically robust, but the ferrites and their attachments are weak under tensile and thermal stresses and tend to crack. Based on prior work on HOM loads for high current storage rings and for an ERL injector cryomodule, a HOM absorber with improved materials and design is being developed for high-gradient SRF systems. This work will use novel construction techniques (without brazing) to maintain the ferrite in mechanical compression. Attachment techniques to the metal substrates will include process techniques for fully-compressed ferrite rings. Prototype structures will be fabricated and tested for mechanical strength under thermal cycling conditions.
 
 
TUOBS2 Cornell ERL Research and Development 729
 
  • C.E. Mayes, I.V. Bazarov, S.A. Belomestnykh, D.H. Bilderback, M.G. Billing, J.D. Brock, E.P. Chojnacki, J.A. Crittenden, L. Cultrera, J. Dobbins, B.M. Dunham, R.D. Ehrlich, M. P. Ehrlichman, E. Fontes, C.M. Gulliford, D.L. Hartill, G.H. Hoffstaetter, V.O. Kostroun, F.A. Laham, Y. Li, M. Liepe, X. Liu, F. Löhl, A. Meseck, A.A. Mikhailichenko, H. Padamsee, S. Posen, P. Quigley, P. Revesz, D.H. Rice, D. Sagan, V.D. Shemelin, E.N. Smith, K.W. Smolenski, A.B. Temnykh, M. Tigner, N.R.A. Valles, V. Veshcherevich, Y. Xie
    CLASSE, Ithaca, New York, USA
  • S.S. Karkare, J.M. Maxson
    Cornell University, Ithaca, New York, USA
 
  Funding: Supported by NSF award DMR-0807731.
Energy Recovery Linacs (ERLs) are proposed as drivers for hard X-ray sources because of their ability to produce electron bunches with small, flexible cross sections and short lengths at high repetition rates. The advantages of ERL lightsources will be explained, and the status of plans for such facilities will be described. In particular, Cornell University plans to build an ERL light source, and the preparatory research for its construction will be discussed. This will include the prototype injector for high current CW ultra-low emittance beams, superconducting CW technology, the transport of low emittance beams, halo formation from intrabeam scattering, the mitigation of ion effects, the suppression of instabilities, and front to end simulations. Several of these topics could become important for other modern light source projects, such as SASE FELs, HGHG FELs, and XFELOs.
 
slides icon Slides TUOBS2 [5.632 MB]