Computer Analysis of X-Ray Spectra

The X-ray full energy peaks from semiconductor detectors are generally described by Gaussian distribution, modified to allow for tailing. The peak fit to an element J is given by  

x is the channel location at which the function is evaluated. Hj, is the amplitude computed for the reference line of the element j. The symbols p. and CT represent the centroid and width, calculated at the X-ray energy of the line being fitted. The background points are chosen in selected channel regions by determining the local minimum for each region. The background fit at channel x is calculated (by second or third-order polynomial) as  

The peak centroid (p.) and peak width (o) are calculated according to the following linear calibration 

Here E represents the appropriate energy corresponding to channel x, and P s are the fitting parameters. The second of the equation gives the dependence 

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