During the operation of radioactive ion-beam facilities, such as the recently decommissioned National Superconducting Cyclotron Laboratory (NSCL) and the newly operational Facility for Rare Isotope Beams (FRIB), many radioisotopes get deposited along beamlines in components such as in mass-separator slits, fragment catchers, and beam dumps. The techniques to recover the by-product radioisotopes from these components is called ‘solid-phase isotope harvesting’ or ‘isotope mining’ and can help to meet the increasing demand for radioisotopes in a variety of fields. This technique offers a unique approach to access rare isotopes that are often challenging to produce using conventional methods. A comparative analysis with aqueous-phase (harvesting from water) and gaseous-phase (harvesting from gases) methods also shows the distinct advantages of solid-phase harvesting, including simplified chemistry and enhanced flexibility in collection location and material choice.This work comprises four primary aims, each aiming at advancing the understanding and implementation of solid-phase isotope harvesting. The first is to establish the of proof-of-concept for solid-phase isotope harvesting, with a specific focus on the extraction of 88Zr from irradiated tungsten foils. This aim seeks to demonstrate the feasibility and efficacy of solid-phase harvesting, and enables comparison with aqueous-phase harvesting. The second aim involves the harvesting of 172Hf from a tungsten ‘heavy-met’ alloy beam-blocker/beam-dump that was used to stop unused beams at NSCL. The beam blocker was retrieved after the NSCL facility was decommissioned and was chemically processed to extract 172Hf and to develop a 172Hf/172Lu generator. This work utilizes the proof of concept study from the first aim and exhibits harvesting from a decommissioned component. The third aim involves the production of 172Hf from the conventional method of irradiating natural lutetium foil targets at the Brookhaven Linear Isotope Producer (BLIP), coupled with the development of methodologies for extracting 172Hf followed by creation of several 172Hf/172Lu generators. This aim helps to compare radionuclides produced by a conventional technique to those obtained from the isotope harvesting efforts shown in the second aim. The fourth aim demonstrates production and separation of 7Be from natural and enriched boron targets, followed by chemical separation, 7Be source preparation and 7Be beam delivery to users at NSCL. This aim demonstrates the practical application of solid-phase isotope harvesting by producing a specific radionuclide for use in scientific experiments. Collectively, this work describes the radioanalytical techniques and chemical methodologies used in the extraction and purification of embedded radioisotopes from beam-irradiated solid materials of tungsten, boron and lutetium. These four aims have together laid the groundwork for developing robust methodologies to extract and separate long-lived radioisotopes that will accumulate along the FRIB beamline. Ultimately, this work aims to enable solid-phase isotope harvesting on a larger scale at FRIB, when FRIB is operational at full beam power, and at other similar ion-beam facilities. The methods described herein allow harvesting of difficult-to-produce byproduct radionuclides without the need for dedicated beamtime at FRIB.
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