Neutron Elastic Scattering Cross Sections for ¹⁶O Between 9 and 15 MeV

Differential cross sections are reported for elastic scattering of neutrons from ¹⁶O. Source neutrons were provided by the D(d,n)³He reaction with average neutron energies of 9.21, 9.71, 10.21, 10.70, 10.95, 11.15, 11.95, 12.45, 12.94, 13.94, and 14.93 MeV. Time-of-flight spectra were obtained for neutrons scattered by a BeO sample at 28 angles from 25 to 160 deg in 5-deg increments. Flight paths of 4 and 6 m were used. Spectra obtained with a separate beryllium sample were subtracted to remove the beryllium scattering contribution. The angular distribution data were corrected for finite source and finite sample-size effects. Legendre polynomial coefficients and total elastic scattering cross sections are reported for oxygen. The data are not well reproduced by the spherical optical model because of the many resonances in the total neutron cross section. Inclusion of resonances together with an optical model background improves the fits to the angular distribution and total cross-section data.