New cross sections for ¹⁶⁵Ho(p,x) reactions focused on production of a perspective Auger electron emitter ¹⁶⁵Er

Erbium-165 is pure Auger electron emitter and promising candidate for targeted radionuclide therapy. Investigation of its production routes is therefore highly desirable. Only a few cross-section measurements of its production via the ¹⁶⁵Ho(p,n) nuclear reaction are available, and the data are not entirely consistent. In this work, we present new cross-section measurements of the ¹⁶⁵Ho(p,n)¹⁶⁵Er reaction and the ¹⁶⁵Ho(p,x)^164m,gHo side reactions covering the proton energy range up to 20 MeV. The obtained data are compared to previously published data as well as to the prediction of the nuclear reaction model code TALYS 1.96. Thick target yields deduced from the measured cross sections confirm feasibility of ¹⁶⁵Er production in clinically relevant amounts and high radionuclidic purity. The investigated production route is particularly suitable for implementation on common small cyclotrons and deserves further development.