Large-scale production of 88Y and 88Zr/88Y generators: A proof of concept study for a 70 MeV H− cyclotron

Abstract The large-scale production of 88Y with proton-induced reactions has been investigated from the perspective of new generation 70 MeV H − cyclotrons. Tandem target configurations are presented for both the direct production of 88Y as well as for producing 88Zr/88Y generators. Based on the relevant excitation functions, physical yields have been derived for 88Y production with Y2O3/SrCO3 tandem targets and 88Zr production with Zr/Y2O3 tandem targets. Yields are presented for optimized targets (i.e. optimum yield) as well as for balanced thermal loads on the individual targets. Liquid 88Zr/88Y generators have been produced using both natural Zr and Nb target materials, the former for dedicated productions and the latter as a byproduct by processing spent irradiated Nb capsules which normally would constitute radioactive waste. These stock solutions, which contain both the target material and 88Zr precursor, are retained virtually unchanged after processing except for the removal of 88Y on AG MP-50 macroporous cation-exchange resin. Methods are presented for the preparation of Nb stock solutions in hydrofluoric acid and Zr stock solutions in sulphuric acid. It is shown that multi-Ci productions of 88Y are feasible at a 70 MeV cyclotron facility, suitable for the needs of fracking applications. In addition, 88Zr/88Y generators can provide 88Y with very high specific activity, suitable for labelling of biomolecules. LA-UR-20-24305.