photon exitance, $M p$

Also contains definition of: specific photon emission

Synonym: photon emittance

Photon flux, number basis, $q p$ , emitted by an element of the surface containing the source point under consideration divided by the area $S$ of that element. SI unit is $s −1 m −2$ .

Notes:

Mathematical definition: $d q p / d S$ . If $q p$ is constant over the surface area considered, $M p = q p / S$ .
Formerly called photon emittance.
This quantity can be expressed on a chemical amount basis by dividing $M p$ by the Avogadro constant. In this case the symbol is $M n , p$ , the name 'photon exitance, amount basis', SI unit is $mol s −1 m −2$ ; common unit is $einstein s −1 m −2$ .

Source:

PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 394

Related index:

IUPAC > Gold Book > math/physics > quantities

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Cite as:
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. https://doi.org/10.1351/goldbook.

Last update: 2014-02-24; version: 2.3.3.

DOI of this term: https://doi.org/10.1351/goldbook.P04631.

Original PDF version: http://www.iupac.org/goldbook/P04631.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 The PDF version is out of date and is provided for reference purposes only.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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