1989 Volume 38 Issue 429 Pages 617-622
When the X-ray stress analysis is performed by using a position sensitive proportional counter (PSPC), a parabolic (curved) background line is obtained on the X-ray diffraction profile because of geometrical problem of PSPC and absorption of X-rays. Since such phenomenon is especially remarkable in the broadened profile, it is necessary to correct it to a straight background for measuring a diffraction angle or a half-value breadth with high accuracy.
This paper analyzes such curvature of background line of the profile and suggests a correction method to linearize the background line.
The results obtained are summarized as follows:
1) The intensities at the both ends of effective length of the PSPC decreased because of the tilt incidence of X-ray beam.
2) The correcting factor for the linearization of the background line was essentially the inverse of background intensity. However, because the background is apt to scatter due to the statistical property of X-rays, such factor was determined by smoothing the inverse of the scattering X-ray intensity obtained from a glass plate.
3) By correcting the background line, the half-value breadth was able to be measured as a constant value wherever the starting points for determining the background line by digital calculation were positioned.
4) On the other hand, the correction was not necessary on the stress measurement.
