EVALUATION OF THE RESPONSE MATRIX OF A BONNER SPHERE SPECTROMETER WITH LII DETECTOR FROM THERMAL-ENERGY TO 100 MEV

The neutron responses of a Bonner sphere spectrometric system with a 4 mmx4 mm (LiI)-Li-6 scintillator have been calculated using the MCNP Monte Carlo code in the energy range from thermal to 100 MeV. Calculated responses have been interpolated to evaluate the response matrix with 51 energy points and 33 sphere diameters. Responses have been parametrized as a function of sphere mass by a hybrid log-normal function. Finally, the new response matrix has been compared with others reported in the literature and with recent experimental findings.