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DOI:10.18429/JACoW-SRF2015-THPB088
Title 20 kW CW Power Couplers for the APS-U Harmonic Cavity
Authors
  • M.P. Kelly, A. Barcikowski, Z.A. Conway, D. Horan, M. Kedzie, S.H. Kim, P.N. Ostroumov
    ANL, Argonne, Illinois, USA
  • S.V. Kutsaev
    RadiaBeam, Santa Monica, California, USA
  • J. Rathke
    AES, Medford, New York, USA
Abstract A pair of 20 kW CW adjustable RF power couplers optimized for 1.4 GHz have been designed and are being built as part of the APS-U bunch lengthening system. The system uses one superconducting RF cavity to be installed into the APS Upgrade electron storage ring and will provide a tremendous practical benefit to the majority of users by increasing the beam lifetime by 2-3 times. The 80 mm diameter, 50 Ω coaxial couplers include 4 cm (~20 dB) of adjustability. This allows optimization of bunch lengthening for a range of storage ring beam currents and fill patterns while, simultaneously, maintaining the required 0.84 MV harmonic cavity voltage. To provide bunch lengthening, the cavity/coupler system must extract RF power (up to 32 kW) from the beam. Each coupler will transmit roughly half of the total extracted power to external water-cooled loads. The design extends upon on a well-tested ANL two RF window concept, using a pair of simple rugged 80 mm diameter alumina disks. A new feature is the ‘hourglass-shaped’ inner conductor chosen to maximize transmission at 1.4 GHz. Results of electromagnetic and thermal simulations, as well as, prototyping and initial RF testing are presented.
Funding This work supported by the U.S. DOE, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. This research used resources of ANL’s ATLAS facility, which is a DOE Office of Science User Facility.
Paper download THPB088.PDF [4.131 MB / 3 pages]
Conference SRF2015, Whistler, BC, Canada
Series International Conference on RF Superconductivity (17th)
Proceedings Link to full SRF2015 Proccedings
Session Poster Session
Date 17-Sep-15   14:30–17:40
Main Classification SRF Technology - Ancillaries
Keywords cavity, Windows, operation, storage-ring, electron
Publisher JACoW, Geneva, Switzerland
Editors Robert E. Laxdal (TRIUMF, Vancouver, BC, Canada); Jana Thomson (TRIUMF, Vancouver, BC, Canada); Volker RW Schaa (GSI, Darmstadt, Germany)
ISBN 978-3-95450-178-6
Published December 2015
Copyright
Copyright © 2015 by JACoW, Geneva, Switzerland     CC-BY Creative Commons License
cc Creative Commons Attribution 3.0