photon flux \(q_{\textrm{p}}\), \(\mathit{\Phi}_{\textrm{p}}\)

https://doi.org/10.1351/goldbook.P04636
Number of photons (quanta of radiation, \(N_{\textrm{p}}\)) per time interval. SI unit is \(\textrm{s}^{-1}\).
Notes:
  1. Mathematical definition: \(q_{\textrm{p}} = \textrm{d}N_{\textrm{p}}/\textrm{d}t\). If the number of photons is constant over the time interval, \(q_{\textrm{p}} = N_{\textrm{p}}/t\).
  2. This quantity can be used on a @C01019@ basis by dividing the photon flux, number basis, \(q_{\textrm{p}}\), by the @A00543@, the symbol then being \(q_{\textrm{n,p}}\), the name 'photon flux, amount basis', SI unit is \(\textrm{mol s}^{-1}\); common unit is \(\textrm{einstein s}^{-1}\).
  3. Although the symbol recommended by CEI is \(\psi_{\textrm{p}}\), the symbol \(q_{\textrm{p}}\) is preferred since \(\psi\) is reserved for @Q04991@.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 395 [Terms] [Paper]