Instrumental epithermal neutron activation analysis of solid geochemical samples

Geochemical samples have been irradiated for 25 h, let decay for 4 ... 6 days and measured for 0.5 h. The measurements were carried out with a gamma spectrometer equipped with a sample changer and an on-line microcomputer for computing the elemental concentrations. The concentrations for 27 elements have been determined: Na, Sc, Cr, Fe, Co, Ni, Zn, As, Se, Br, Rb, Mo, Ag, Sn, Sb, Cs, Ba, La, Sm, Eu, Lu, Hf, Ta, W, Au, Th and U. The precision of the analysis is typically +-7 %. The accuracy was investigated by analyzing USGS geochemical standards and it was found to be satisfactory. Using one gamma spectrometer, about 7000 samples can be analyzed per annum.