Fit of EDXRF spectra with a genetic algorithm

In energy-dispersive x-ray fluorescence analysis, the estimation of the net area of the peaks is a primary requirement. This task requires a non-linear fitting of the peaks. The most common procedures are based on the Marquardt-Levenberg technique. This technique generally works well only when the spectrum is perfectly known, i.e. all the peaks are recognized. Moreover, it is sometimes difficult to introduce constraints on the fit due to peak shape or other physical properties. In this paper a new technique is proposed, based on a set of genetic operators. It works well even when the knowledge of the peaks is incomplete and it also allows one easily to introduce constraints. The results obtained with this algorithm are generally superior with respect to a standard implementation of a Marquardt-Levenberg procedure. The only drawback is the speed of convergence, that is slower than in the Marquardt-Levenberg technique.