Application of a Bonner sphere spectrometer for the determination of the angular neutron energy spectrum of an accelerator-based BNCT facility

• Bonner sphere spectrometer is used to determine the angular neutron energy spectrum of an accelerator-based BNCT facility.
• The shadow-cone technique is a method used with Bonner sphere spectrometer to remove the neutron scattered contribution.
• The response function matrix for the set of Bonner sphere spectrometer is calculated by Monte Carlo code.
• Unfolding codes are used to obtain neutron spectra at different neutron emission angles (0°, 40°, 80° and 120°).

Experimental activities are underway at INFN Legnaro National Laboratories (LNL) (Padua, Italy) and Pisa University aimed at angular-dependent neutron energy spectra measurements produced by the 9Be(p,xn) reaction, under a 5 MeV proton beam. This work has been performed in the framework of INFN TRASCO-BNCT project. Bonner Sphere Spectrometer (BSS), based on 6LiI (Eu) scintillator, was used with the shadow-cone technique. Proper unfolding codes, coupled to BSS response function calculated by Monte Carlo code, were finally used. The main results are reported here.