Qualitative and quantitative analysis using different intensity ratios based on combined EDXRF and MCNP simulations

In this study, a Monte Carlo simulation framework based on MCNP (version 6.2) was developed to perform qualitative and quantitative analysis of an Energy-Dispersive X-Ray Fluorescence (EDXRF) system using a standardization approach based on emitted and scattered X-rays. For qualitative analysis, samples were prepared by diluting uranyl acetate ((CH3COO)2UO2.2H2O) with cellulose (C6H10O5). For quantitative analysis, different matrix compositions were produced using uranyl acetate together with palladium(II) chloride (PdCl2), antimony(III) chloride (SbCl3), and barium chloride (BaCl2). The samples were irradiated with 59.54 keV gamma rays emitted from a 185 Gbq (5Ci) Am-241 annular radioactive source, and the emitted and scattered X-rays were detected using an HPGe detector. Calibration curves were established by correlating the ratios of characteristic uranium l -line intensities (Ll and Lα1,2) and scattered X-ray intensities (coherent and Compton) with effective atomic numbers and uranium concentrations. The MCNP simulation results showed good agreement with the experimental measurements, confirming the reliability of the proposed approach. The main contribution of this study is the demonstration that MCNP-assisted standardization can effectively reduce matrix effects, including absorption–enhancement, inhomogeneity, and particle-size effects, thereby improving the accuracy and reliability of EDXRF analysis. Furthermore, the proposed methodology provides a practical framework for extending XRF studies to radioactive systems that are difficult or impractical to investigate experimentally.