Cold-neutron disk-chopper spectrometer at J-PARC

K. Nakajima, M. Nakamura, R. Kajimoto, T. Osakabe, K. Kakurai, M. Matsuda, M. Metoki, S. Wakimoto, T. J. Sato, S. Itoh, M. Arai, K. Yoshida, K. Niita

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


We are constructing a cold-neutron double-chopper spectrometer for the new spallation neutron source at the Materials and Life Science Facility (MLF), J-PARC. The spectrometer is dedicated to inelastic and quasi-elastic measurements in the cold and thermal neutron incident energy region of Ei = 1-80 meV. Looking at a H2-coupled moderator and employing a combination of two fast disk-choppers, one as the pulse-shaping and another as the monochromating chopper, the spectrometer realizes both high intensity and fine resolution. The expected neutron flux at the sample position is of the order of 104-107 n/cm2/s depending on Ei (e.g. 106 n/cm2/s at Ei = 20meV with ΔE/Ei = 3%). The newly developed fast diskchopper enables a fine and tunable energy resolution (ΔE/Ei ≥ 1% at Ei = 20 meV). A large area detector bank (±1358 in horizontal, -22-+30° in vertical and 1.3π in solid angle) covers wide momentum transfer range with the resolution of a few percent of ΔQ/ki, where ΔQ is the uncertainty in the longitudinal component of the scattering vector. The spectrometer is planned to be ready in 2008, when the first neutron beam at MLF, J-PARC is expected.

Original languageEnglish
Pages (from-to)13-21
Number of pages9
JournalJournal of Neutron Research
Issue number1
Publication statusPublished - 2007 Jan 1
Externally publishedYes


  • Chopper spectrometer
  • Disk-chopper
  • Inelastic neutron scattering
  • J-PARC

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering


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