Scattering of Neutrons by Carbon from 7 to 9 MeV

Abstract
Differential elastic cross sections for neutrons scattered by carbon were measured for 7.20-, 7.35-, 7.73-, 8.20-, and 9.00-MeV incident neutron energies using the Aerospace Research Laboratory neutron time-of-flight facility. The inelastic differential cross sections for neutrons leaving the residual C12 nucleus in the 4.43-MeV excited state were also measured for 7.73-, 8.20-, and 9.00-MeV incident neutrons. These data have uncertainties relative to the normalizations of 1.5 to 8% for the elastic cross sections and 4 to 18% for the inelastic cross sections. The normalization uncertainty is 4%. The elastic angular distributions are compared to optical-model calculations using the Rosen potential. Neither this potential nor any other with reasonable geometry fits the data. The angle-integrated cross sections combined with previously reported C12(n, α)Be9 cross sections are compared to the total neutron cross sections at 7.73, 8.20, and 9.00 MeV. Because of the several strongly over-lapping resonances in the 7-9-MeV energy region, a unique phase-shift analysis of the data is not possible.