The quantity used to characterize the scattered intensity at the
scattering angle

,
defined as

,
where

is the intensity of the incident radiation,

is the total intensity of scattered radiation observed at an
angle

and a distance

from the point of
scattering and

is the
scattering volume. The factor

takes account of
polarization phenomena. It depends on the type of radiation employed.
-
For light scattering, dependent on the polarization of the incident beam,
for vertically polarized light,
for horizontally polarized light and
for unpolarized light.
-
For small-angle neutron scattering,
.
-
For small-angle X-ray scattering,
, if
.
Source:
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.