Optimization of GEM detectors for applications in X-ray fluorescence imaging

In this work a set of simulations that aim at the optimization of Micropattern Gaseous Detectors (MPGD) for applications in X-ray fluorescence imaging in the energy range of 3 - 30 keV is presented. By studying the statistical distribution of electrons from interactions of X-rays with gases, the energy resolution limits after charge multiplication for 6 keV X-ray photons in Ar/CO2(70/30) 2 (70/30) and Kr/CO2(90/10) 2 (90/10) were calculated, resulting in energy resolutions of 15.4(4)% and 14.6(2)% respectively. These two mixtures were studied in simulations to evaluate the advantages of using krypton-based mixtures to reduce the presence of escape peaks in fluorescence spectra. A model to evaluate the X-ray fluorescence from the conductive materials inside the detectors was implemented, serving as a tool to estimate the extent of contamination of fluorescence spectra when using copper or aluminum layers in the material composition of MPGDs.