Index

Image CIF dictionary (imgCIF) version 3.00.04

_diffrn_radiation.div_x_y_source

Definition:

   
     Beam crossfire correlation degrees^2^ between the
     crossfire laboratory X-axis component and the crossfire
     laboratory Y-axis component (see AXIS category).
     This is a characteristic of the X-ray beam as it illuminates
     the sample (or specimen) after all monochromation and
     collimation.
     This is the mean of the products of the deviations of the
     direction of each photon in XZ plane times the deviations
     of the direction of the same photon in the YZ plane
     around the mean source beam direction.  This will be zero
     for uncorrelated crossfire.
     Note that some synchrotrons, this value is specified in
     milliradians^2^, in which case a conversion would be needed.
     To go from a value in milliradians^2^ to a value in
     degrees^2^, multiply by 0.180^2^ and divide by \p^2^.

Type: Real

Units: degrees_squared

Category:
diffrn_radiation