photoelectric peak

Synonym: photopeak

Of a spectrum of γ-radiation, the part of the spectral response curve corresponding to the absorption in the radiation detector by the photoelectrical effect of the detected γ-energy. In most cases the peak also contains events caused by multiple processes and use of the expression total absorption peak or full energy peak is to be preferred. Synonymous with photopeak.
PAC, 1982, 54, 1533 (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1548