Harvesting 62Zn from an aqueous cocktail at the NSCL

Abstract

“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 ⁶²Zn from an aqueous matrix irradiated with a 150 MeV per nucleon ⁷⁸Kr beam, while synergistically capturing other gaseous reaction products. In addition to the production rate for ⁶²Zn (9.08(30) × 10^{−5 62}Zn per incoming ⁷⁸Kr), the rates of formation for several other radionuclides were determined as well. The purification of ⁶²Zn 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 ⁶²Zn. With the decay of ⁶²Zn the radioactive daughter ⁶²Cu is generated, and with the isolation of pure ⁶²Cu eluate, the principle of a medical radionuclide generator could be demonstrated. To illustrate the applicability of the obtained ⁶²Zn, 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.