Calibration of a bonner sphere spectrometer in quasi-mono-energetic high-energy neutron fields

Pioch, C.*; Mares, V.*; Rhm, W.*; Iwase, Hiroshi*; Iwamoto, Yosuke   ; Tamii, Atsushi*; Shima, Tatsushi*; Hatanaka, Kichiji*; Nakamura, Takashi*

Calibration measurements for a Bonner sphere spectrometer with He proportional counter were performed in quasi-mono-energetic neutron fields at the Research Center for Nuclear Physics (RCNP) at the Osaka University. Neutron fields with nominal peak energies of 244 MeV and 387 MeV were generated via Li(p,n)Be reactions. The neutron spectra were determined by BSS measurements in the range from peak energy down to thermal energies using the MSANDB unfolding code, and three different sets of response functions calculated by GEANT4. The neutron spectra above 10 MeV were also measured by means of the time-of-flight (TOF) method applying NE213 liquid organic scintillators. Within the uncertainties involved in the experiment a remarkable overall agreement of the measurements and response calculations was observed.