Monte Carlo simulations of energy dispersive X-ray fluorescence (EDXRF) of liquid and metallic samples: A comparison and experimental validation of MCNP and XRMC codes

The present study compares numerical simulations carried out by two Monte Carlo codes, the Monte Carlo N-Particle (MCNP) and the XRMC, of Energy Dispersive X-ray fluorescence (EDXRF) excited in liquid and metallic samples. The results are validated by measurements with a laboratory-made equipment, consisting of a mini X-ray tube (Moxtek, Inc., 4 W, Ag target) and a Si PIN detector model X123 (Amptek, Inc.), configured in the usual 45°/45° geometry. The liquid sample was a multielementar stock solution from High Purity Standards containing traces of the transition metals Cu, Fe, Mn, and Zn. For the solid samples, two metallic plates of standard reference materials were used, namely, a) a rectangular plate (6.9 mm × 43.4 mm, 1.5 mm thick) made of high purity copper; and b) a steel alloy plate (Duplex 2205 CRM) containing Si, Cr, Mn, Fe, Ni, Cu and Mo in its composition. The quantitative analysis of the relative peak intensities between the simulations and experiment reveals a difference of 0.4 % to 12.3 %, depending on the elemental characteristic line and sample composition. The results show an overall very good agreement between the simulations of the MCNP and XRMC codes with the experimental spectra, making them suitable for typical EDXRF applications involving metallic samples and multielement aqueous solutions. • Validated Monte Carlo simulations of EDXRF carried out by MCNP and XRMC codes. • X-ray fluorescence excited in copper, steel plates and in a standard liquid sample. • Relative errors between 0.4 % and 12.3 % depending on the elemental characteristic line. • Overall very good agreement between simulations of MCNP and XRMC with experiments.