Total cross sections of C, Ca, Ti, Ba, La, Ce, Nd, Sm, Gd, Er, Ta, Au, and Pb for neutrons of energies between 13.1 and 15.6 Mev have been measured by the transmission technique with good geometry. The range of neutron energy was achieved by observing neutrons at various angles from thin tritium targets bombarded by deuterons of energy up to 450 kev. Geometry was such that a scattering in the sample of more than about 2° removed the neutron from the beam to the stilbene scintillation detector. The total cross section of carbon for neutrons was found to vary from 1.41 barns at 13.1 Mev to a minimum of 1.31 barns at 14.2 Mev to 1.49 barns at 15.6 Mev. Other elements showed smaller cross-section variation with energy.

• Received 30 September 1957

DOI:https://doi.org/10.1103/PhysRev.109.1268