Experimental and computational techniques for the analysis of proton beam propagation through a target stack

Proton beam energy, energy straggling, and intensity in thick stacks of target materials at the Los Alamos Isotope Production Facility were investigated using the foil activation technique and computational simulations. Isotopic yield measurements of irradiated foils from several recent experiments used to determine these quantities were compared with the predictions of MCNP6 and TRIM codes, and with Andersen & Ziegler’s semi-empirical formalism. Differences between code predictions and experimental data were examined. Methods for computational simulation of energy propagation agree well with one another and were able to accurately predict the proton beam’s energy for a limited range. Predictions were accurate when degrading from an initial energy of 100 MeV down to approximately 50 MeV, but struggled to represent measured data well at lower energies.