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photon flux, q p, Φ p

Number of photons (quanta of radiation, N p) per time interval. SI unit is s −1.
  1. Mathematical definition: q p = d N p / d t. If the number of photons is constant over the time interval, q p = N p / t.
  2. This quantity can be used on a chemical amount basis by dividing the photon flux, number basis, q p, by the Avogadro constant, the symbol then being q n , p, the name 'photon flux, amount basis', SI unit is mol s −1; common unit is einstein s −1.
  3. Although the symbol recommended by CEI is Φ p, the symbol q p is preferred since Φ is reserved for quantum yield.
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 395
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IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook.
Last update: 2014-02-24; version: 2.3.3.
DOI of this term: doi:10.1351/goldbook.P04636.
Original PDF version: http://www.iupac.org/goldbook/P04636.pdf. The PDF version is out of date and is provided for reference purposes only. For some entries, the PDF version may be unavailable.
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