14-MeV Neutron Activation Analysis of Complex Materials

In principle, activation analysis of chemical samples by use of 14-MeV neutrons (Fast Neutron Activation Analysis, or FNAA) is a straightforward instrumental technique. As attempts are made to improve the accuracy and precision of the method, and to use the technique for several elements in a wider variety of samples, however, several important effects must be considered. These are categorized as instrumental, chemical, or nuclear and are examined briefly. It may be concluded that most determinations by FNAA are not "routine" except in the case of determination of a single element in a series of closely related samples in one laboratory. Some of the parameters are examined in more detail and illustrated with examples from mostly coal analyses performed in the authors' laboratory.