1. L. Xiao, LHC-crab-cavity WebEx meeting, Dec.09, 2008 Baseline Design: Significant coupling of input power to LOM/SOM couplers FPC HOM Update on LHC Crab Cavity Conceptual Design LOM/SOM

2. L. Xiao, LHC-crab-cavity WebEx meeting, Dec.09, 2008 Alternative Design 1: Power coupler, HOM couplers in between of the two cells Maintain field symmetry in LOM/SOM coupler regions Avoid cross coupling between FPC and LOM/SOM couplers Coax TM110-pi coupler rejects operating mode using field symmetry. FPC Waveguide: TM110-0 mode Coax: TM110-pi mode Coax-to-coax: LOM/SOM modes Coax-to-coax: LOM/SOM modes HOM

3. L. Xiao, LHC-crab-cavity WebEx meeting, Dec.09, 2008 Alternative Design 2: Only TM110-0/π mode couplers in between of the two cells LOM/SOM HOM Operating mode in coaxial beampipe The center conductor will be slightly bent so that the rotating flange can adjust the tip of the center conductor to lie exactly along the E-field node of the operating mode field.