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https://doi.org/10.18429/JACoW-IPAC2018-TUPAL022
Title Low-Reflection RF Window for ACS Cavity in J-PARC Linac
Authors
  • J. Tamura, Y. Kondopresenter, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • H. Ao
    FRIB, East Lansing, USA
  • F. Naito, M. Otani
    KEK, Tokai, Ibaraki, Japan
  • Y. Nemoto
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
Abstract In the Japan Proton Accelerator Research Complex (J-PARC) linac, the Annular-ring Coupled Structure (ACS) cavities have been stably operating. To maintain this operation availability, we manufactured three backups of the pillbox-type RF windows for the ACS cavities in fiscal year 2015 and 2017. It is desirable to minimize the RF reflection of the RF window to prevent standing waves from exciting between the cavity and the RF window, and not to significantly change the optimized coupling factor between the cavity and the waveguide. To realize the minimization, the relative permittivities of the ceramic disks of the RF windows were evaluated by measuring the resonant frequencies of the pillbox cavity containing the ceramic disk. On the basis of the evaluated relative permittivities, the pillbox-part lengths of the RF windows were determined. The measured Voltage Standing Wave Ratios (VSWRs) of the manufactured RF windows are just about 1.08 and these are applicable for the practical use.
Paper download TUPAL022.PDF [0.856 MB / 3 pages]
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Conference IPAC2018, Vancouver, BC, Canada
Series International Particle Accelerator Conference (9th)
Proceedings Link to full IPAC2018 Proccedings
Session MC4 Poster Session
Date 01-May-18   09:00–12:00
Main Classification 04 Hadron Accelerators
Sub Classification A08 Linear Accelerators
Keywords cavity, Windows, linac, proton, impedance
Publisher JACoW Publishing, Geneva, Switzerland
Editors Shane Koscielniak (TRIUMF, Vancouver, BC, Canada); Todd Satogata (JLab, Newport News, VA, USA); Volker RW Schaa (GSI, Darmstadt, Germany); Jana Thomson (TRIUMF, Vancouver, BC, Canada)
ISBN 978-3-95450-184-7
Published June 2018
Copyright
Copyright © 2018 by JACoW, Geneva, Switzerland     CC-BY Creative Commons License
cc Creative Commons Attribution 3.0