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A flowing-water target was irradiated with a 150 MeV/nucleon beam of 78Kr at the National Superconducting Cyclotron Laboratory to produce 77Kr and 76Kr. Real-time gamma-imaging measurements revealed the mass transport of the krypton radioisotopes through the target-water processing, or "isotope harvesting", system. The production rates were determined to be 2.7(1) × 10–4 nuclei of 76Kr and 1.18(6) × 10–2 nuclei of 77Kr formed per incident 78Kr ion. Utilizing an off-gas processing line as part of the isotope harvesting system, a total of 7.2(1) MBq of 76Kr and 19.1(6) MBq of 77Kr were collected in cold traps. Through the decay, the daughter radionuclides 76Br and 77Br were generated and removed from the traps with an average efficiency of 77 ± 12%. Due to the differences in half-lives of 76Kr and 77Kr, it was possible to isolate a pure sample of 76Br with 99.9% radionuclidic purity. The successful collection of krypton radioisotopes to generate 76Br and 77Br demonstrates the feasibility of gas-phase isotope harvesting from irradiated accelerator cooling-water. Larger-scale collections are planned for collecting by-product radionuclides from the Facility for Rare Isotope Beams. [ABSTRACT FROM AUTHOR]

An experiment was performed at the National Superconducting Cyclotron Laboratory using a 140 MeV/nucleon 48 Ca beam and a flowing-water target to produce 47 Ca for the first time with this production route. A production rate of 0.020 ± 0.004 47 Ca nuclei per incoming beam particle was measured. An isotope harvesting system attached to the target was used to collect radioactive cationic products, including 47 Ca, from the water on a cation-exchange resin. The 47 Ca collected was purified using three separation methods optimized for this work: (1) DGA extraction chromatography resin with HNO 3 and HCl, (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 47 Ca 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 47 Ca. For the first time, this experiment demonstrated the feasibility of the production, collection, and purification of 47 Ca through isotope harvesting for the generation of 47 Sc for nuclear medicine applications., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)