Of an irradiated element for a specified isotope, the steady state reached when the disintegration rate of the nuclide formed is equal to its production rate.
Source:
PAC, 1994, 66, 2513
(Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994))
on page 2525
Transformed and rewritten from PDF version (entry
http://www.iupac.org/goldbook/S05473.pdf)
by: Miloslav Nic, Jiri Jirat, Bedrich Kosata, ICT Prague, Czech Republic