Speaker
Description
Part of the HiLumi LHC upgrade includes the use of superconducting Niobium crab cavities. The two proposed cavity designs are the Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD). The DQW crab cavity will be tested in the Super Proton Synchrotron (SPS) at CERN in 2018. Both cavities require Higher Order Mode (HOM) couplers to prevent beam excited HOMs from perturbing the crabbing regime.
HOM couplers commonly have complex geometries which are often difficult to machine/manufacture. Small geometric errors which result from manufacturing processes can incur large offsets in the filter’s operation, meaning tight tolerances are often needed. In order to quantify that these tolerances have been adhered to, and hence that the designed operation of the filter has been met, test-boxes have been developed which are capable of providing broadband analysis of the HOM couplers.
The test-boxes have been designed to allow both the spectral analysis at low power but with the further possibility of allowing high power conditioning of the Niobium couplers before installation onto the cavities. Thus far the designs of both test boxes have been completed with construction and assembly currently taking place at both Lancaster University and CERN.
