Evaluation of gamma-ray and neutron energy for area monitoring system in the IFMIF/EVEDA accelerator building

Hiroki Takahashi, Sunao Maebara, Hironao Sakaki, Keiichi Hirabayashi, Kosuke Hidaka, Nobuhiro Shigyo, Yukinobu Watanabe, Kenshi Sagara

Research output: Contribution to journalArticlepeer-review


The engineering validation of the IFMIF/EVEDA prototype accelerator, up to 9 MeV by supplying the deuteron beam of 125 mA, will be performed at the BA site in Rokkasho. A design of this area monitoring system, comprising of Si semiconductors and ionization chambers for covering wide energy spectrum of gamma-rays and 3He counters for neutrons, is now in progress. To establish an applicability of this monitoring system, photon and neutron energies have to be suppressed to the detector ranges of 1.5 MeV and 15 MeV, respectively. For this purpose, the reduction of neutron and photon energies throughout shield of water in a beam dump and concrete layer is evaluated by PHITS code, using the experimental data of neutron source spectra. In this article, a similar model using the beam dump structure and the position with a degree of leaning for concrete wall in the accelerator vault is used, and their energy reduction including the air is evaluated. It is found that the neutron and photon flux are decreased by 10 4-order by employing the local shields using concrete and polyethylene around beam dump, and the photon energy can be suppressed in the low energy.

Original languageEnglish
Pages (from-to)1235-1238
Number of pages4
JournalFusion Engineering and Design
Issue number7-8
Publication statusPublished - Aug 2012

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • General Materials Science
  • Mechanical Engineering


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