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Nakamura, N.

Paper Title Page
MOPAN034 Development of a Pulsed Sextupole Magnet System for Beam Injection at the Photon Factory Storage Ring 230
  • Y. Kobayashi, K. Harada, T. Honda, T. Miyajima, S. Nagahashi
    KEK, Ibaraki
  • N. Nakamura, H. Takaki
    ISSP/SRL, Chiba
  We proposed a single pulsed sextupole system for beam injection in electron storage rings. Now we are going to design a pulsed sextupole magnet and a ceramic chamber and install them at the Photon Factory storage ring next summer. The required specifications of the magnet and the vacuum chamber are estimated using a multi-particle tracking simulation. In this conference, we describe the design of the hardware for the system and the field measurement of the pulsed magnet.  
TUPMN042 Simulation Study of Resistive-wall Beam Breakup for ERLs 1010
  • N. Nakamura, H. Sakai, H. Takaki
    ISSP/SRL, Chiba
  For future ERL-based light sources, average beam current is required to be up to 100 mA. Such a high-current multi-bunch beam may generate and cumulate strong long-range wake-fields by interaction with accelerator components such as superconducting cavities and vacuum ducts, and as a result, strong beam breakup(BBU) may occur. Resistive-wall BBU due to narrow and resistive vacuum ducts has been hardly studied, though the effects of BBU due to HOMs of superconducting cavities were much investigated. Asymptotic expressions of transverse resistive-wall BBU were derived for a beam that passes through a uniform resistive pipe under uniform external focusing*. However the expressions are valid only for limited parameter ranges and initial conditions. Therefore we have developed a computer simulation program to study transverse multi-bunch resistive-wall BBU more minutely and generally. In this paper, we will present the simulation results obtained by the simulation program and also compare them with the asymptotic expressions.

* J. M. Wang and J. Wu, PRST-AB 7, 034402(2004)

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.