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, {ₒ}{ₓ}, as a function of energy for an "unknown" sample in terms of a calibration target for which ({ₒ}{ₓ}) (E) is known. The agreement between the experimental determination of ({ₒ}{ₓ}) (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, =0. 172 ev, ₍=0. 0211 ev, R₉=₁=1. 03 barn^, R₉=₂=0. 917 barn^.