Spectrum isotopes library

The electron-positron annihilation line

β, γ radiation
Main emission lines: 511keV

Where detected

If an isotope decays to produce positrons, they react with environmental electrons and turn into two gamma rays with an energy of 511 keV. Fluorine-18, for example, is common and is used for diagnostics in PET imaging. It is also possible to acquire such a spectrum by meeting a person in a hospital or subway after such a study.