Harvesting 62Zn from an aqueous cocktail at the NSCL

Isotope harvesting is a technique that offers access to exotic radionuclides created as by-products during nuclear science research. Ongoing exploratory work at the National Superconducting Cyclotron Laboratory (NSCL) is directed towards the production and extraction of rare radionuclides from a flowing-water target and intends to pave the way for future harvesting efforts at the upcoming Facility for Rare Isotope Beams (FRIB). Here we present the collection of Zn-62 from an aqueous matrix irradiated with a 150 MeV per nucleon Kr-78 beam, while synergistically capturing other gaseous reaction products. In addition to the production rate for Zn-62 (9.08(30) x 10(-5 62)Zn per incoming Kr-78), the rates of formation for several other radionuclides were determined as well. The purification of Zn-62 from a large number of co-produced radionuclides was performed by anion exchange chromatography, allowing the isolation of 80.5(5.2)% of the generated Zn-62. With the decay of Zn-62 the radioactive daughter Cu-62 is generated, and with the isolation of pure Cu-62 eluate, the principle of a medical radionuclide generator could be demonstrated. To illustrate the applicability of the obtained Zn-62, the isolated product was used in free and DTPA-labelled form in a proof of principle plant uptake study with garden cress employing phosphor imaging for visualization.