added by archaeologs A method of Principle. A specimen or sample is irradiated in a nuclear reactor. In the nuclear reactions that result, stable atoms of the material are transformed into radioactive isotopes. These isotopes start to decay immediately, and emit gamma rays, whose energy is related to the elements present in the sample. The energy and intensity of these gamma rays can be detected, and from this information, the concentrations of different elements may be determined. Materials. Small objects may be left intact, but larger objects require a sample of 50- lOOmg to be removed. The technique has been used to analyse glasses (natural and man-made), flint, pottery and metals (as coins). Applications. Neutron activation analysis has proved useful in determining the origin of flint artefacts, by matching the trace element concentrations with those of flint from various sources. Similar studies have been carried out on obsidian and pottery. Coins can be analysed non-destructively by neutron activation, and the technique has been used widely to investigate their major and minor elements.
The Macmillan dictionary of archaeology, Ruth D. Whitehouse, 1983