single escape peak

https://doi.org/10.1351/goldbook.S05686
In a γ-ray spectrum, the peak due to @P04398@ in the detector and escape, from the sensitive part of the detector, of one of the @P04627@ of \(511\ \text{keV}\) resulting from @A00366@.
Source:
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1541 [Terms] [Paper]