||Development of the high-energy neutron fluence rate standard field in Japan with a peak energy of 45 MeV using the 7Li(p,n)7Be reaction at TIARA
清藤, 一 ,
倉島, 俊 ,
西野, 翔 ,
吉富, 寛 ,
Journal of Nuclear Science and Technology
538 , 2017-02 , Taylor and Francis
In this study, we developed a 45 MeV neutron fluence rate standard of Japan. Quasimonoenergetic neutrons with a peak energy of 45 MeV in the neutron standard field were produced by the 7Li(p,n)7Be reaction using a 50-MeV proton beam from an azimuthally varying field (AVF) cyclotron of the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA). The neutron energy spectrum was measured using an organic liquid scintillation detector and a 6Li-glass scintillation detector by the time-of-flight method, and using a Bonner sphere spectrometer by the unfolding method. The absolute neutron fluencewas determined using a proton recoil telescope (PRT) composed of the liquid scintillation detector and a Si(Li) detector that was newly developed in the present study. The detection efficiency of the PRT was obtained using the MCNPX code. The peak neutron production cross section for the 7Li(p,n)7Be reaction was also derived from the neutron fluence in order to confirm the neutron fluence of the TIARA high-energy neutron field. The peak neutron production cross section obtained in the present study was in good agreementwith those of previous studies. The characteristics of the 45-MeV neutron field in TIARAwere successfully evaluated in order to calibrate high-energy neutron detectors and high-energy neutron dosimeters.