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

Technical Report · Wed Sep 01 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7346628· OSTI ID:7346628

Cramer, S. N.; Oblow, E. M.

Monte Carlo calculations were performed to analyze an integral experiment on a liquid oxygen sample to determine the adequacy of the neutron scattering and gamma-ray production data for oxygen. The experimental results included energy- and angular-dependent NE-213 detector count rates and secondary pulse-height spectra for scattered neutrons and gamma rays. The sample was a spherical dewar of liquid oxygen pulsed with a 1- to 20-MeV neutron source. Pulse-height data were unfolded to generate secondary neutron and gamma-ray production spectra as a function of angle in broad incident neutron energy bins. Analysis of all the reported data was based on multigroup Monte Carlo calculations using the MORSE code. Results indicate that the current ENDF/B-IV neutron and gamma-ray production data for oxygen above 1 MeV appear to be in good order. The only major discrepancy uncovered was related to neutron scattering and gamma-ray production from first level inelastic scattering interactions. Calculated results for the production of 6-MeV gamma rays from the 6-MeV first inelastic level in oxygen appear to be low by around 50 percent at energies above the inelastic threshold. Likewise, calculated secondary neutron spectra for incident neutron energies above 6 MeV are uniformly low at energies corresponding to neutrons having had first level inelastic scattering events in oxygen. Additional deficiencies in the oxygen cross-section data are indicated for inelastic scattering from the cluster of discrete levels in the 12-13 MeV range and for elastic scattering at very small angles at energies above 2 MeV. The size of the inelastic discrepancies are larger than the 20-30 percent order of error indicated for these cross sections in the ENDF/B-IV uncertainty files for oxygen.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 7346628
• Report Number(s): ORNL/TM-5535
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
CAPTURE
CRYOGENIC FLUIDS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
GAMMA RADIATION
HADRON REACTIONS
INELASTIC SCATTERING
IONIZING RADIATIONS
LIQUIDS
MONTE CARLO METHOD
MULTIGROUP THEORY
NEUTRAL-PARTICLE TRANSPORT
NEUTRON FLUX
NEUTRON REACTIONS
NEUTRON TRANSPORT
NEUTRON TRANSPORT THEORY
NONMETALS
NUCLEAR REACTIONS
NUCLEON REACTIONS
OXYGEN
RADIATION FLUX
RADIATION TRANSPORT
RADIATIONS
SCATTERING
TRANSPORT THEORY