155Tb from natural targets: Reaction modeling of natTb(p, x) and natGd(α, x)

Abstract

Four terbium radionuclides (149Tb, 152Tb, 155Tb and 161Tb) are promising key players in the field of radiopharmaceutical production: in particular 155Tb emits Auger-electrons and γ rays suitable respectively for therapy and for SPECT imaging. In this work we investigate and compare two 155Tb generators by considering reactions of protons on natTb and of alpha particles on natGd for energies E<70 MeV. Both routes can be studied using intermediate energy cyclotrons for the production of 155Dy, the precursor of 155Tb. The two production routes are analyzed with the nuclear reaction code TALYS by varying the parameters of the models to improve the agreement between the calculated cross sections and the available experimental data. Realistic theoretical simulations for the production of 155Tb are performed by optimizing the activity and the purity of the final product, with a full simulation of the radiochemical separation procedure.