The energy released by the decay and carried off by the gamma ray is characteristic of the particular isotope undergoing decay. Detection and measurement of gamma ray intensities permits identification and precise quantification of radioisotopes present.


This spectrum reveals the gamma ray energies released from an activated sample of coal fly ash (NIST1633a), following a 1-m irradiation and 15-m decay.

Peaks in the spectrum indicate the presence of aluminum (at 1779 keV), vanadium (1434 keV), and manganese (846 keV).

4. Gamma spectra:

Oregon State University Archaeometry Lab