Total Cross Sections for 14-Mev Neutrons

Abstract

With deuterons from the electrostatic generator of the Department of Terrestrial Magnetism incident on a tritium-zirconium target, and with the neutrons detected by a terphenylxylene scintillator and photomultiplier, total cross sections of C, H, D, O, and N for 14.10±0.05 Mev neutrons were measured. The effective neutron energy was evaluated from the kinematics of the $\mathrm{T}\mathrm{}(d,n)\mathrm{}{\mathrm{He}}^4$ reaction, the dependence of the reaction's cross section on energy and angle, and the multiple scattering of the deuterons and their rate of energy loss in the target. A least squares analysis of the transmissions of six thicknesses each of carbon and polyethylene (40 to 85 percent transmissions) yielded, for total cross sections $\sigma$ in barns: ${\sigma }_{\mathrm{C}}=1.279\mathrm{}\pm 0.004$ and ${\sigma }_{\mathrm{H}}=0.689\mathrm{}\pm 0.005$. Transmissions of light and heavy water gave ${\sigma }_{\mathrm{D}}=0.803\mathrm{}\pm 0.014$ and ${\sigma }_{\mathrm{O}}=1.64\mathrm{}\pm 0.04$. Transmission of melamine gave ${\sigma }_{\mathrm{N}}=1.7\mathrm{}\pm 0.1$.