Using X-ray precession photography method

the stacking fault configu-rations and their probability in single crystal ZnS have been determinated first in present paper

[1]

. In this paper

some factors affecting precession measurement have been studied and the results are represented as follows.(1) The comparison between the orientafion-photography and the cone-axis-photography to determinate the crystal orientation have been carried out experimently. When the size of cross section in ZnS single crystal is 0.1 to 0.2mm

the orientation-photography is available

while the specimen is very small

the cone-axis-photography will be adoptabie for this purpose.(2) The influences of crystal orientation deviation on intensity distribution on the plane of reciprocal lattice have been studied. When the b axis deviates from the vertical direction in about 1º

the reflection spots en (10·

l

) row located at zero-level a*c* of the reciprocal lattice are splitted. Whenthe deviation of the b axis is 0.5º

the reflection spots are not splitted butit influences the profile of intensity distribution. While the deviation is 0ºapproximately (about 7' in experiment)

where the b axis is almost theprecession axis

the profile of the intensity distribution is symmetric alongc* direction.(3) The influences of time-of-reflection on the intensity distribution of (10·l) row on zero-level a*c* precession photography have been investigated. After Lorentz-polarization correction carried out

the profile of intensity distribution is variated obviously

as a result the values of integrated width of the (10·

l

) row are affected by Lorentz-polarization correction

which indicates that this correction is necessary in analysis.Other related factors

such as background

overlap

double-spots and absorption effects

which should be noted in the precession photography experiments

are also discussed.