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TY - CONF AU - Mitchell, J.A. AU - Apsimon, R. AU - Ben-Zvi, I. AU - Burt, G. AU - Calaga, R. AU - Castilla, A. AU - Jones, T.J. AU - Macpherson, A. AU - Powers, T. AU - Shipman, N.C. AU - Verdú-Andrés, S. AU - Wang, H. AU - Xiao, B. P. AU - Zwozniak, A. ED - Schaa, Volker RW ED - He, Yuan ED - Li, Lu ED - Zhao, Ning TI - Simulation and Measurements of Crab Cavity HOMs and HOM Couplers for HL-LHC J2 - Proc. of SRF2017, Lanzhou, China, July 17-21, 2017 C1 - Lanzhou, China T2 - International Conference on RF Superconductivity T3 - 18 LA - english AB - Two Superconducting Radio-Frequency (SRF) crab cavities are foreseen for the High Luminosity LHC (HL-LHC) upgrade. Preliminary beam tests of the Double Quarter Wave (DQW) crab cavity will take place in the Super Proton Synchrotron (SPS) in 2018. For damping of the cavity's Higher Order Modes (HOMs) the DQW has three identical on-cell, superconducting HOM couplers. The couplers are actively cooled by liquid heluim. In this paper, electromagnetic simulations of the HOMs and HOM couplers are presented. A novel approach to pre-installation spectral analysis of the HOM couplers is then presented, detailing both simulated and measured data. Measurements of the cavity HOMs at warm and in Vertical Test Facilities (VTFs) at both JLAB and CERN are detailed, comparing the measured characteristics of each mode to that of the simulated data-sets. Finally, the measured cavity data is compared with the test box measurements to see by what extent any reduction in damping can be predicted. PB - JACoW CP - Geneva, Switzerland SP - 881 EP - 885 KW - ion KW - HOM KW - cavity KW - damping KW - simulation DA - 2018/01 PY - 2018 SN - 978-3-95450-191-5 DO - 10.18429/JACoW-SRF2017-THPB059 UR - http://jacow.org/srf2017/papers/thpb059.pdf ER -