Production, Collection, and Purification of 47Ca for the Generation of 47Sc through Isotope Harvesting at the National Superconducting Cyclotron Laboratory

An experiment was performed at the National Superconducting Cyclotron Laboratory using a 140 MeV/nucleon Ca-48 beam and a flowing-water target to produce Ca-47 for the first time with this production route. A production rate of 0.020 +/- 0.004 Ca-47 nuclei per incoming beam particle was measured. An isotope harvesting system attached to the target was used to collect radioactive cationic products, including Ca-47, from the water on a cation-exchange resin. The Ca-47 collected was purified using three separation methods optimized for this work: (1) DGA extraction chromatography resin with HNO3 and HCI, (2) AG MP-50 cation-exchange resin with an increasing concentration gradient of HCl, and (3) AG MP-50 cation-exchange resin with a methanolic HCl gradient. These methods resulted in >= 99 +/- 2% separation yield of Ca-47 with 100% radionuclidic purity within the limits of detection for HPGe measurements. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to identify low levels of stable ions in the water of the isotope harvesting system during the irradiation and in the final purified solution of Ca-47. For the first time, this experiment demonstrated the feasibility of the production, collection, and purification of Ca-47 through isotope harvesting for the generation of 'Sc for nuclear medicine applications.