A COMPUTER-PROGRAM TO ANALYZE X-RAY-DIFFRACTION FILMS

We have developed a Macintosh computer program to analyze Debye-Scherrer x-ray powder diffraction films digitized with a conventional scanner. The program uses a fast derivatives-free procedure to fit distorted ellipses corresponding to the diffraction rings on the film. These ellipses are collapsed into a one-dimensional plot of intensity versus scattering angle, from which one can extract information about the diffraction pattern that would have been lost in visual reading. Moreover, uncertainties are decreased by a factor of approximately 30 over visual reading, and the analysis of diffraction films is reduced to a matter of minutes.