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photon exposure, H p

Photon irradiance, E p, integrated over the time of irradiation for a beam incident from all upward directions. SI unit is m −2.
Notes:
  1. Mathematical definition: H p = ∫ t E p ⁢ d t. If the photon irradiance is constant over the time interval, H p = E p t.
  2. This term refers to a beam not scattered or reflected by the target or its surroundings. For a beam incident from all directions photon fluence (H p , o, F p , o) is an equivalent term.
  3. This quantity can be used on a chemical amount basis by dividing H p by the Avogadro constant, the symbol then being H n , p, the name 'photon exposure, amount basis', SI unit is mol m −2; common unit is einstein m −2.
Source:
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 394
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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. doi:10.1351/goldbook.
Last update: 2014-02-24; version: 2.3.3.
DOI of this term: doi:10.1351/goldbook.P04632.
Original PDF version: http://www.iupac.org/goldbook/P04632.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 The PDF version is out of date and is provided for reference purposes only.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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