Procedure and apparatus for the determination of the gold content in a material containing gold

This patent describes a method and apparatus for determining the gold content of materials, and in particular, of rock and stone samples. The procedure is based upon the irradiation of the material with neutrons and the determination of the intensity of the gamma radiation (279 keV) produced in the reaction 197Au(n,n')sup(197m)Au. The neutron source used produces the neutrons by the deuteron-deuteron or deuteron-beryllium reaction. The energy of these neutrons is not high enough for producing fast neutron reactions in the other elements of the material. The apparatus described separates the samples with a gold content above a certain value by means of the procedure described above. (Th.P.)