Analysis of ore samples employing photon activation of the metastable states of gold and silver

The analytical method described here uses inelastic gamma scattering to pro duce Au-197m(T-1/2 = 7.8 s), Ag-107m(T-1/2 = 44.2 s) and Ag-109m(T-1/2 = 39 .8 s) with the subsequent measurement of residual activity. Bremsstrahlung radiation from linear electron accelerator with maximum gamma quanta of 6 t o 9 MeV is optimum for this purpose. Induced activity from gold and silver was measured with a HPGe. To obtain maximum sensitivity for detection, it i s advantageous to measure both gamma and X-ray activity. Possible interfere nces were studied in detail, using the pure element spectra and also litera ture data. The most evident advantage of the method is its rapidity and rel atively low cost of analysis, (C) 1999 Elsevier Science B.V. All rights res erved.