The Energy Dependence of the Resonant Scattering of Slow Neutrons from Gold

The energy dependence of slow neutrons scattered from a thick gold target has been measured using a newly developed scattering chamber in conjunction with the Columbia slow neutron velocity spectrometer. A method of analysis has been developed for determining the ratio of the scattering cross section to the total cross section, σₛσₜ, as a function of energy for an "unknown" sample in terms of a calibration target for which (σₛσₜ)(E) is known. The agreement between the experimental determination of (σₛσₜ)(E) for gold in the energy range 0.7 to 8 ev and the Breit-Wigner theory is excellent. All the level parameters can be evaluated by combining these scattering data with the results of transmission experiments and the cross section for self-indication. The final results for the 4.9-ev gold level are: $J=1$, Γ=0.172 ev, ΓN=0.0211 ev, RJ=1=1.03 barn^, RJ=2=0.917 barn^.