radiant (energy) flux [obsolete], P, Φ

https://doi.org/10.1351/goldbook.R05044
This obsolete term is not recommended. In
photochemistry
,
radiant power
, P, is adopted. SI unit is W.
Note:
P is preferred, because in
photochemistry
, Φ is reserved for
quantum yield
.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 409 [Terms] [Paper]