Methodology for a fast determination of EDX Si(Li) detector response function in the 5 keV to 15 keV range

Abstract

Standard methods used for establishing EDX Si(Li) detectors response functions (DRF) are tedious and require a significant amount of work and beam time, which is not always available. That fact frequently leads to the disregard of the specific DRF at the time of the measurement, and to the fit of spectra using “general” response functions, which were determined on detectors with different characteristics. The accurate description of the low energy side asymmetry of the peaks is necessary to quantify trace elements accurately and to determine fundamental parameters like X-ray intensity ratios and ionization cross sections. In the present work, a simple method to monitor the energy dependence of EDX detectors response function in the 5 keV to 15 keV range is presented. Four PIXE generated X-ray spectra of thin mono-elemental (Ti, Fe, Ni, and Au) films are shown to be enough for this purpose. The methodology can be used as a laboratory-based protocol to establish the DRF and to monitor it over time.