average life

in nuclear chemistry
Defined for an @A00493@ or nuclear system in a specified state. For an exponentially decaying system, it is the average time for the number of atoms or @N04256@ in a specified state to decrease by a factor e. Synonymous with @M03780@.
PAC, 1982, 54, 1533. (Glossary of terms used in nuclear analytical chemistry (Provisional)) on page 1536 [Terms] [Paper]