Keyword: higher-order-mode
Paper Title Other Keywords Page
MOPB012 First RF Measurement Results for the European XFEL SC Cavity Production cavity, HOM, controls, factory 195
  • A.A. Sulimov, P.B. Borowiec, V. Gubarev, J. Iversen, D. Kostin, G. Kreps, K. Krzysik, A. Matheisen, W.-D. Möller, D. Reschke, W. Singer
    DESY, Hamburg, Germany
  The first reference cavities (RCV) for the European XFEL Project are being tested within the collaboration of Research Instruments (RI), E. ZANON, IFJ-PAN and DESY: - production and warm RF measurements of cavities and their components at RI and ZANON; - surface preparation at DESY; - cold RF tests at DESY by IFJ-PAN. Purpose of the RCV is to establish a stable cavity fabrication and qualification of the surface preparation infrastructure at industry. All necessary RF measurements were done, starting with mechanical fabrication in 2011, till the tuning and cold cavity RF tests in 2012. We present the first results of RF measurements within RCV production for the European XFEL.  
poster icon Poster MOPB012 [1.843 MB]  
MOPB016 In-situ Measurement of Beam-induced Fields in the S-band Accelerating Structures of the Diamond Light Source linac linac, multipole, dipole, wakefield 204
  • C. Christou
    Diamond, Oxfordshire, United Kingdom
  The Diamond pre-injector linac uses two 5.2 m DESY linac II-type accelerating structures to generate a 100 MeV electron beam suitable for injection into the booster synchrotron. The structures are powered independently by two high-power S-band klystrons and are designed to operate at 3 GHz. Higher order modes up to 14 GHz induced by beam in unpowered accelerating and bunching structures have been directly measured using directional couplers in the high-power waveguide network. These modes are compared with an electromagnetic simulation of the structures. The negative impact of higher-order wakes on the bunch trains used at Diamond is considered, and the use of the multipole field measurement for alignment of the beam to the structure is investigated.