Analysis of a neutron scattering and gamma-ray production integral and experiment on silicon dioxide for neutron energies from 1 to 15 MeV

Abstract

Monte Carlo calculations were made to analyze the results of an integral experiment with a sample of SiO/sub 2/ to determine the adequacy of ENDF/B-IV neutron scattering and gamma-ray production cross-section data for silicon and oxygen. The experimental results analyzed included energy-dependent NE-213 detector neutron and gamma-ray count rates at a scattering angle of 90 deg and pulse-height spectra for scattered neutrons and gamma rays. The experiments were carried out with the ORELA 1- to 20-MeV pulsed neutron source. The pulse-height data were unfolded to generate secondary neutron and gamma-ray spectra at 90 deg as a function of incident neutron energy. Multigroup Monte Carlo calculations using the MORSE code and ENDF/B-IV cross sections were made to analyze all reported results. No outstanding discrepancies between calculated and measured responses were found on the neutron data below 12 MeV. Possible discrepancies in the inelastic scattering data above 12 MeV are indicated. This is consistent with a previous analysis of an oxygen experiment. A more detailed analysis will have to be performed before any definite conclusions can be drawn from these comparisons.