1. General principles

1.1 Purpose of irradiation and different irradiation modes

The aim of irradiation is to create radioisotopes that can be reliably identified and precisely quantified after irradiation. These radioisotopes must therefore have a non-negligible probability of being produced from the elements to be assayed, and their lifetime must be long enough to allow their detection. To determine the totality of elements, it is necessary to use several irradiation modes. Table 1 summarizes the characteristics of those most commonly used in activation analysis. In practice, the choice will depend on the properties of the radioisotopes created in the sample from the element(s) to be assayed and the other elements present.