Use of polycapillary X-ray lenses in the X-ray diffraction measurement of texture

Abstract

Corrections for instrumental aberrations of X-ray diffraction texture measurements (pole-figure measurements) conducted in quasi-parallel-beam geometry using an X-ray lens have been investigated on the basis of measurements on (texture-free) reference samples. It has been shown that a defocusing correction, which is a major correction in the case of pole figures recorded with divergent-beam geometries, is not necessary when a parallel beam, produced by an X-ray lens, is used. In this case, the major instrumental sources of error stem from the illumination of areas outside the sample surface,i.e.the finite sample size, and the finite area of the detector, both giving rise to a reduction of the recorded signal. Two correction procedures for this reduction, an experimental one and a numerical one, have been tested and are described.