Accession Number : AD0759994

Title :   A Program for Least-Squares Analysis of Fourier Coefficients of Peak Shapes and Comparisons of Old and New Procedures.

Descriptive Note : Technical rept.,

Corporate Author : NORTHWESTERN UNIV EVANSTON ILL DEPT OF MATERIALS SCIENCE

Personal Author(s) : Kidron,A. ; Cohen,J. B.

Report Date : 01 MAY 1973

Pagination or Media Count : 100

Abstract : At least two ways are now available of performing Fourier analysis of peak shape, the older direct ransform method and a new procedure involving least-squares. In addition, there are at least three procedures in the literature of treating the Fourier coefficients to correct for the main errors in the method due to the difficulty in establishing the true background. In the report a new enlarged version of a program for the least-squares procedure is presented along with comments on how to detect errors. This procedure is compared to the transform method. It is shown that both procedures give essentially similar results for particle size and strain. The computing time for the least-squares procedure is an order of magnitude greater. It is thus most useful when there are severe problems due to peak overlap and portions of the data must be removed. But under most situations the transform method is adequate and less expensive. (Author Modified Abstract)

Descriptors :   (*CRYSTAL STRUCTURE, *X RAY DIFFRACTION), (*FOURIER ANALYSIS, LEAST SQUARES METHOD), INTEGRAL TRANSFORMS, COMPUTER PROGRAMS, CURVE FITTING, GRAPHICS

Subject Categories : Statistics and Probability
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE