Interference from uranium in neutron activation analysis or rare-earths in silicate rocks

A direct nondestructive method of analysis for²⁴¹Am utilizing photon counting and self-absorption correction factors is presented. The method gives favorable agreement for samples analyzed by radiochemical separation procedures and alpha particle spectrometry. The comparison was made over a range of approximately five orders of magnitude of²⁴¹Am concentrations. The method is reliable and relatively simple. Sensitivity for a ∼5-g sample and a counting intervals of 60 000 s is ∼0.2 pCi/g with an uncertainty of ±22%, which decreases to ±11% for increased counting intervals of 150 000 s and an increased sample size of ∼20 g.