Neutron spectrometry and dosimetry in 100 and 300 MeV quasi-mono-energetic neutron field at RCNP, Osaka University, Japan

¹ Helmholtz Zentrum München (HMGU), 85764 Neuherberg, Germany
² Technische Universität München, Physik-Department, 85748 Garching, Germany
³ Japan Atomic Energy Agency (JAEA), Tokai, Japan
⁴ National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST), Tsukuba, Japan
⁵ High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
⁶ Research Reactor Institute, Kyoto University, 2-1010 Asashiro-nishi, Kumatori, Sennan, Osaka 590-0494, Japan
⁷ Research Center for Nuclear Physics (RCNP), Osaka University, Mihogaoka, Ibaraki, Japan
⁸ Tohoku University, Sendai, 980-0872, Japan

^a Corresponding author: mares@helmholtz-muenchen

Published online: 25 September 2017

Abstract

This paper describes the results of neutron spectrometry and dosimetry measurements using an extended range Bonner Sphere Spectrometer (ERBSS) with ³He proportional counter performed in quasi-mono-energetic neutron fields at the ring cyclotron facility of the Research Center for Nuclear Physics (RCNP), Osaka University, Japan. Using 100 MeV and 296 MeV proton beams, neutron fields with nominal peak energies of 96 MeV and 293 MeV were generated via ⁷Li(p,n)⁷Be reactions. Neutrons produced at 0° and 25° emission angles were extracted into the 100 m long time-of-flight (TOF) tunnel, and the energy spectra were measured at a distance of 35 m from the target. To deduce the corresponding neutron spectra from thermal to the nominal maximum energy, the ERBSS data were unfolded using the MSANDB unfolding code. At high energies, the neutron spectra were also measured by means of the TOF method using NE213 organic liquid scintillators. The results are discussed in terms of ambient dose equivalent, H^*(10), and compared with the readings of other instruments operated during the experiment.