• N. Solyak, T.J. Peterson, V. Poloubotko, V.P. Yakovlev
  Fermilab, Batavia
• O. Brunner, E. Ciapala, T.P.R. Linnecar, J. Tuckmantel, W. Weingarten
  CERN, Geneva
• R. Calaga
  BNL, Upton, Long Island, New York

Funding: This work has been partially performed under the auspices of the US department of energy

The complex LHC crab cavity design and the beam-line configuration pose very tight constraints for the cryostat design. An initial assessment of the LHC main RF cryostat points to a new design both from the RF and engineering point of view. The cavity and tunnel constraints are discussed in detail and an intial cryostat design along with the cryogenic circuit is presented.

• V.P. Yakovlev, I.G. Gonin, T.N. Khabiboulline, A. Latina, A. Lunin, V. Poloubotko, N. Solyak
  Fermilab, Batavia

Different couplers are described that allow the reduction of both transverse wake potential and RF kick in the SC acceleration structure of ILC. A simple rotation of the couplers reducing the RF kick and transverse wake kick is discussed for both the main linac and bunch compressors, along with possible limitations of this method. Designs of a coupler unit are presented which preserve axial symmetry of the structure, and provide reduced both the RF kick and transverse wake field.