400 MHz LHC Crab Cryomodule with HOM Dampers, Tuners and Couplers

Superconducting radio frequency (SRF) cavities are being successfully used for acceleration of charged particle beams worldwide. The application of the SRF cavities for manipulation of the beam properties in the transverse direction finds more and more applications. The use of superconducting (SC) structures helps maximize the electric field gradient, which is a highly desirable feature for applications involving manipulations of the charged particle beams at the point of delivery, such as Final Focus (FF) point. Application of the parallel bar SC structure in future SRF accelerators will allow a further increase over existing machine performance. Compact equipment utilizing SRF cavities can be successfully used in a broad range of applications from increasing beam luminosity in colliders, to manipulation of the correlation between the longitudinal and transverse phase space projections of the beam particle distribution. This proposal will develop a cryomodule for a 400 MHz superconducting parallel-bar crabbing cavity designed for tilting a proton beam with energy of up to 7 TeV at the Final Focus point. The parallel-bar structure uses a significant transverse asymmetry of the electric field distribution of the fundamental mode, which requires a respective asymmetry of the power coupler. At the same time this intrinsic asymmetry of the cavity design immediately leads to a more complicated HOM spectrum, which makes damping of the unwanted modes in the cavity a non-trivial task. This proposal will design and develop the asymmetric power coupler & amp; pickup, the HOM dampers, both slow and fast frequency tuners, and the microphonic mechanical dampers. All other systems needed for a functional cryomodule (eg: helium transfer lines, magnetic shielding, etc) will also be a part of this project. The final cryomodule design should satisfy the strict requirements and the limitations of the existing tunnel environment of the LHC synchrotron near the FF point.