Item _diffrn_radiation.polarizn_source_norm
Description
The angle in degrees, as viewed from the specimen, between
the normal to the polarization plane and the laboratory Y
axis as defined in the AXIS category.
Note that this is the angle of polarization of the source
photons, either directly from a synchrotron beamline or
from a monchromater.
This differs from the value of
'_diffrn_radiation.polarisn_norm'
in that '_diffrn_radiation.polarisn_norm' refers to
polarization relative to the diffraction plane rather than
to the laboratory axis system.
In the case of an unpolarized beam, or a beam with true
circular polarization, in which no single plane of
polarization can be determined, the plane should be taken
as the X-Z plane, and the angle as 0.
See '_diffrn_radiation.polarizn_source_ratio'.
Category
diffrn_radiation
Mandatory Code
no
Data Type Code
float
Units
degrees
Default Value
0.0
Enumeration Range
| Minimum Value |
Maximum Value |
| 90.0 |
90.0 |
| -90.0 |
90.0 |
| -90.0 |
-90.0 |
