**2. Neutron activation analysis**

Neutron activation analysis (NAA) is a nuclear process used for determining the concentra‐ tions of elements in a vast amount of materials. NAA relies on excitation by neutrons so that the treated sample emits gamma-rays. It allows the precise identification and quantification of the elements, above all of the trace elements in the sample. NAA has applications in chemistry but also in other research fields, such as geology, archaeology, medicine, environ‐ mental monitoring and even in the forensic science.
