Neutron activation analysis of copper in bismuth by γ, γ-coincidence measurement

Copper was determined non-destructively by neutron activation analysis in high-purity bismuth down to concentrations of 30 p.p.b. By using γ, γ-coincidence counting of the annihilation photons of ⁶⁴Cu, interferences from the bremsstrahlung of the matrix could be completely suppressed, together with the interferences due to the induced γ-activities of other impurities as Zn, Cd, Au, Ag, Sb and As.The accuracy of the method was tested by spectrophotometry and by destructive activation analysis. The technique was applied to the analysis of a high-purity bismuth rod.