Origin of the powder diffraction pattern

The data are taken from the ICDD powder diffraction file, record No. 4-836 H.E. Swanson, E. Tatge, National Bureau of Standards (US), Circular 359, 1 (1953). 

The scattered intensity is usually represented as the total number of the accumulated counts, counting rate (counts per second - cps) or in arbitrary units. Regardless of which units are chosen to plot the intensity, the patterns are visually identical because the intensity scale remains linear and because the intensity measurements are normally relative, not absolute. In rare instances, the intensity is plotted as a common or a natural logarithm, or a square root of the total number of the accumulated counts in order to better visualize both strong and weak Bragg peaks on the same plot. The use of these two non-liner intensity scales, however, always increases the visibility of the noise (i.e. highlights the presence of statistical counting errors). A few examples of the non-conventional representation of powder diffraction patterns are found in the next section. 

NIST standard reference material, SRM 660 (see http //srmcatalog.nist.gov/). 

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The use of detectors, collimators and monochromators in different powder diffractometers is discussed in Chapter 3, while the reminder of this chapter is dedicated to theory of diffraction, understanding the origin of the powder diffraction pattern, and a brief description of how structural information can be extracted from powder diffraction data. 

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