activation

in radiochemistry
https://doi.org/10.1351/goldbook.A00095
The process of inducing radioactivity by irradiation. In general, a specification is added of the type of incident radiation (e.g. nuclear, neutron, photon) or its energy (e.g. thermal, fast).
Source:
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2515 (https://doi.org/10.1351/pac199466122513)