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

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 226; p. 112263
• Main Authors: de Souza, G.G.A., da Luz, H.N., Bregant, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2025
• Subjects: Gas Electron Multiplier; GEM copper fluorescence; X-ray fluorescence imaging; GEM copper fluorescence; X-ray fluorescence imaging; Gas Electron Multiplier
• ISSN: 0969-806X
• DOI: 10.1016/j.radphyschem.2024.112263

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 3–30keV is presented. By studying the statistical distribution of electrons from interactions of X-rays with gases, the energy resolution limits after charge multiplication for 6keV X-ray photons in Ar/CO2(70/30) and Kr/CO2(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.
•Optimization studies of large gaseous imaging X-ray fluorescence detectors.•Simulations evaluating the best energy resolutions possible to achieve.•Assessment of spectra contamination by copper fluorescence from detector materials.•Evaluation of the capability to identify different elements by X-ray fluorescence.