KOPSKO: a computer program for generation of Kossel and Pseudo Kossel diffraction patterns

Diffraction techniques are widely used especially as additional tools for a nalytical microprobe analysis. A supplementary device to a scanning electro n microscope (SEM) allows taking of X-ray lattice source and wide angle int erference patterns, now termed Kossel and Pseudo Kossel patterns, respectiv ely, in transmission and back reflection arrangement as reported by DABRITZ ct al. (1986, 1997a,b). The developed program KOPSKO simulates exactly the entire reflection system of Kossel and Pseudo Kossel diffraction patterns basing on the geometric diffraction theory. It permits phase, orientation, and structure determination. The present paper shows the wide range of poss ibilities using the computerized analysis in this field. Initially it deals with simulation of Kossel patterns, which are excellent suitable for a pre cise determination of lattice constants in the micro range for instance. A new way for simulation of Pseudo Kossel diffraction patterns using three di mensional vector algebra to calculate reflections in point by point procedu re is presented in the second part. The attained precise coincidence of sim ulation and experimentally taken Pseudo Kossel patterns allows a relatively easy determination of crystallographic data of mono- and polycrystals. Particularly the program is designed to determine lattice constants precise ly, for the complex divergent beam X-ray interferences, too. Through the th ree dimensional simulation it takes into account shade originated by the ta rget holder. Moreover, the three dimensional point by point procedure enabl es the localization of lattice imperfections as well as the consideration o f grain size effects in polycrystals, which lead to interruptions of Pseudo Kossel lines. By simulation of diffraction patterns of polycrystalline mat erials the study of such specimens is essentially simplified.