Validation of proton energy loss in regolith simulants: PSI Proton Irradiation Facility (PIF) beam tests and MRADSIM simulations

This technical report documents the comparison and validation of proton-beam measurements performed at the Paul Sherrer Institute (PSI) Proton Irradiation Facility (PIF) with MRADSIM simulations for Martian regolith simulants once processed by Spark Plasma Sintering at the University of Cagliari. Thin targets of two regolith formulations (MGS-1 and JEZ-1) with thicknesses of (Formula presented) and (Formula presented) were irradiated under multiple degrader settings, spanning approximately 30–(Formula presented) proton energies at the regolith surface. Experimental detector-response spectra were calibrated using regolith-free reference runs, and peak energies were extracted using Gaussian fits. The PIF geometry was imported into MRADSIM toolkit via GDML, and the regolith simulants were implemented as composite materials. Simulated detector observables were obtained in a downstream (Formula presented) -thick LYSO scintillator detector volume, enabling direct experiment–simulation benchmarking of the peak deposited energy and the transmitted-proton fluence. In addition, several Geant4 hadronic physics lists were evaluated using a reduced chi-square ((Formula presented) ) analysis to select a robust baseline model for regolith transport within the validated energy range.