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Shinoe, K.

Paper Title Page
TUPMN046 Quadrupole HOM Damping with Eccentric-fluted Beam Pipes 1022
 
  • M. Sawamura
    JAEA/ERL, Ibaraki
  • T. Furuya, S. Sakanaka, T. Suwada, T. Takahashi, K. Umemori
    KEK, Ibaraki
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  
  HOM damping is important for superconducting cavities, especially for high current CW machines such as ERLs. The lower Q-values of HOMs lead to the lower requirement of a refrigerator system and the higher beam current against HOM BBU. Enlarged beam pipes, which have lower cutoff frequencies, are effective to damp HOMs of monopole and dipole, but insufficient for HOMs of quadrupole which have high cutoff frequencies. An eccentric-flute is proposed to damp the HOMs of quadrupole. The eccentric-flute is formed by displacing the flute from the center of the beam pipe and/or by jackknifing around the midpoint of the flute to couple two degenerate modes. The eccentric-flute acts as a mode converter from quadrupole to dipole of the lower cutoff frequency so that the RF power can propagate through the beam pipe. The result of calculation with MAFIA and measurement of a cold model with the eccentric-flute are presented.  
TUPMN044 Status of R&D Efforts Toward the ERL-based Future Light Source in Japan 1016
 
  • T. Kasuga, T. A. Agoh, A. Enomoto, S. Fukuda, K. Furukawa, T. Furuya, K. Haga, K. Harada, S. Hiramatsu, T. Honda, K. Hosoyama, M. Izawa, E. Kako, H. Kawata, M. Kikuchi, Y. Kobayashi, M. Kuriki, T. Mitsuhashi, T. Miyajima, S. Nagahashi, T. Naito, T. Nogami, S. Noguchi, T. Obina, S. Ohsawa, M. Ono, T. Ozaki, S. Sakanaka, H. Sasaki, S. Sasaki, K. Satoh, M. Satoh, T. Shioya, T. Shishido, T. Suwada, M. Tadano, T. Takahashi, Y. Tanimoto, M. Tawada, M. Tobiyama, K. Tsuchiya, T. Uchiyama, K. Umemori, S. Yamamoto
    KEK, Ibaraki
  • R. Hajima, H. Iijima, N. Kikuzawa, E. J. Minehara, R. Nagai, N. Nishimori, M. Sawamura
    JAEA/ERL, Ibaraki
  • H. Hanaki, H. T. Tomizawa
    JASRI/SPring-8, Hyogo-ken
  • A. Ishii, I. Ito, H. Kudoh, N. Nakamura, H. Sakai, S. Shibuya, K. Shinoe, H. Takaki
    ISSP/SRL, Chiba
  • M. Katoh, A. Mochihashi, M. Shimada
    UVSOR, Okazaki
  
  Energy Recovery Linacs (ERL), based on superconducting accelerators, are one of the most promising synchrotron light sources in future. The KEK and the JAEA, in collaboration with the ISSP, the UVSOR, and the SPring-8, are considering to realize together the ERL-based next-generation light source in Japan. To establish key technologies for that, active R&D efforts started. The R&D program includes the developments of ultra-low-emittance photocathode guns and of superconducting cavities, as well as experimental proofs of accelerator-physics issues at the ERL test facility, which will be built at the KEK campus. We are currently working on constructing a prototype photocathode gun, on designing superconducing cavities, and on designing a prototype ERL. The current plan of the prototype ERL comprises a full injector linac, one or two cryomodules for the main linac, and the beam return loop, which can be operated at beam energies from 60 to 160 MeV. The up-to-date R&D status will be reported.