THE DIFFERENTIAL NEUTRON SCATTERING CROSS SECTION OF OXYGEN BETWEEN 6 AND 15 MEV


Gerd Börker, Reinhard Böttger, Hein J. Brede, Horst Klein, Wolf Mannhart, Bernd R.L. Siebert

Physikalisch-Technische Bundesanstalt, D-3300 Braunschweig, Fed. Rep. of Germany

The elastic and inelastic scattering of neutrons from a water sample has been investigated at 9 energies between 6 and 15 MeV using the D(d,n)3He source reaction. Special care was taken with the Monte Carlo simulation of sample size effects and multiple scattering corrections and the efficiency determination of the NE213 detectors. Uncertainties of 3 ... 8 % were obtained for the differential elastic cross section resulting in 2.5 % uncertainties for the angle-integrated cross section σel which was normalized with respect to the simultaneously measured n-p scattering. The differential cross sections show deviations of up to a factor of two from the ENDF/B-V data file, whereas deviations of up to 15 % were found in σel. The inelastic scattering to the first pair of state in 16O at 6.1 MeV could also be extracted, but with larger uncertainties due to kinematic interference with elastically scattered neutrons from the D(d,np)D reaction.

KEYWORDS: 16O, En = 6 - 15 MeV, scattering cross sections, efficiency of NE213 detectors, time-of-flight spectrometer