IUPAC > Gold Book > alphabetical index > P > photon fluence, H p , o, F p , o


photon fluence, H p , o, F p , o

Amount of photons (quanta of radiation) incident on a small sphere from all directions, divided by the cross-sectional area of that sphere and integrated over time. Photons per surface area (quanta m −2). SI unit is m −2.
  1. Mathematical definition: H p , o = F p , o = d N p / d S = ∫ t E p , o ⁢ d t with E p , o the photon fluence rate, integrated over the duration of the irradiation, t. If E p , o is constant over the time interval, H p , o = F p , o = E p , o t
  2. This quantity can be used on a chemical amount basis by dividing H p , o by the Avogadro constant, the symbol then being H n , p , o, the name 'photon fluence, amount basis', SI unit is mol m −2; common unit is einstein m −2.
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.P04634.
Original PDF version: http://www.iupac.org/goldbook/P04634.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 The PDF version is out of date and is provided for reference purposes only.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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