Implementation of a spectrum fitting procedure using a robust peak model

摘要

The need for an accurate description of characteristic x-ray lines has led to the development of complex peak models that combine a Gauss, a shelf and a tail function. Via relationships that describe the shelf and tail parameters as a function of the energy, it is possible to reduce the number of fit parameters significantly. In this work, we carried out an experiment to study the shelf and tail parameters obtained with an HPGe detector. We observed a strong discontinuity in the shelf and tail parameters around the K-edge energy of Ge. This indicates that these parameters are strongly dependent on the mass-attenuation coefficient of the detector material. Therefore, we propose relationships that describe those parameters as a function of the energy and the mass-attenuation coefficient. The implementation of these relationships in a fitting procedure results in a more robust fitting procedure with a much smaller number of fitting parameters. Excellent fits for HPGe spectra can be obtained. Because the detector dependence seems to be fairly general, we could successfully apply the model to Si(Li) spectra also. Copyright (C) 2003 John Wiley Sons, Ltd. [References: 22]