Goldbook title
IUPAC > Gold Book > alphabetical index > P > photon fluence rate, E p , o
Related index:
IUPAC > Gold Book > math/physics > quantities
Gold G Icon
Indexes Download

photon fluence rate, E p , o

Rate of photon fluence. Total number of photons (N p) incident from all directions on a small sphere divided by the cross-sectional area of the sphere and per time interval. SI unit is m −2 s −1. Same as photon spherical irradiance.
  1. Mathematical definition: E p , o = d N p / d t d S = d H p , o / d t. If E p , o is constant over the time interval and the surface, E p , o = N p / t S Equivalent definition: E p , o = ∫ 4 π L p ⁢ d Ω with L p the photon radiance and Ω the solid angle of the beams passing through the given point on the surface.
  2. It reduces to photon irradianceE p for a parallel and normally incident beam not scattered or reflected by the target or its surroundings.
  3. This quantity can be used on a chemical amount basis by dividing E p , o by the Avogadro constant, the symbol then being E n , p , o, the name 'photon fluence rate, amount basis', SI unit is mol m −2 s −1; common unit is einstein m −2 s −1.
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 395
Related index:
IUPAC > Gold Book > math/physics > quantities
Interactive Link Maps
First Level Second Level Third Level
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: (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
Last update: 2014-02-24; version: 2.3.3.
DOI of this term:
Original PDF version: The PDF version is out of date and is provided for reference purposes only. For some entries, the PDF version may be unavailable.
Current PDF version | Version for print | History of this term