Measurement of intensity of directionally diffuse streaks on a four-circle diffractometer: divergence correction factors for bisecting setting

Because of the inherent beam divergence, point intensities measured using a four-circle diffractometer at equispaced points along the diffuse streak correspond to variable lengths of the streak. Correction factors required to convert the measured intensities into those corresponding to a fixed length at each equispaced point along the diffuse streak are derived for two different crystal mountings under bisecting geometry. A procedure for experimentally verifying the mathematical approach employed in these calculations is also described.