Electromagnetic isotope separation of gadolinium isotopes for the production of 152,155Tb for radiopharmaceutical applications

Abstract A demo experiment was performed at the tandem accelerator of MLL Garching where 152Tb was produced by irradiating a unique ion-implanted 152Gd target ( > 99% enriched) with 8 and 12 MeV protons respectively. At these energies mainly 152Tb was produced by (p,n) reactions plus a small quantity of 153Tb by (p, γ ) reactions. Upper limits are derived for co-production of other Tb isotopes. The achieved radionuclidic purity would enable direct use for human applications. Gd isotopes of adequate isotopic enrichment could be separated with the SIDONIE mass separator at CSNSM Orsay and prepared as cyclotron targets suited for high current irradiations. In a demo experiment samples of highly enriched 158Gd were produced at SIDONIE. The sample purity was characterized by prompt gamma activation analysis at NPI Řež. The neighboring mass 157Gd was found to be suppressed by three to five orders of magnitude, depending on the sample position in the SIDONIE separator.