Isotope Harvesting at Heavy-Ion Fragmentation Facilities

Isotope harvesting from heavy-ion fragmentation facilities is a potential source of isotopes of interest for applications research. With the upgrade of the National Superconducting Cyclotron Laboratory (NSCL) to the Facility for Rare Isotope Beams (FRIB) usable quantities of many isotopes of interest will be produced and available for harvest from an aqueous beam dump. If available, these isotopes would be of interest to a broad range of applications such as medicine, geology, and stockpile stewardship. Preliminary experiments were performed at the NSCL in order to determine the feasibility of isotope harvesting at (FRIB). A water target station that consisted of a 100 mL beam dump was designed and built to collect secondary beams at the NSCL. This target station could be controlled remotely from outside of the experimental vault allowing for multiple collections with minimal exposure to radioactivity. Three secondary beam collections were made with the water target station: a 24Na beam, an analyzed 67Cu beam, and an unanalyzed 67Cu beam. To test the durability of the target station, a 73% pure 85 MeV/u 24Na secondary beam was stopped and collected in the beam dump. Multiple collections were made with currents up to 2 x 106 particles per second without visible radiolytic damage to the target cell. The station operated without any observed release of radiolytic gases, spills, or loss of radioactive liquids. The water target station was then used collect a 77% pure 76 MeV/u 67Cu secondary beam. 67Cu was separated from the other secondary beam contaminants with an average recovery of 88 ± 3 % and used to radiolabel an antibody. The radiochemical yield of 67Cu-NOTA-Bz-NCS-Trastuzumab was \u3e95%. To better mimic the conditions that would be present in the beam dump at FRIB an unanalyzed beam was collected. This secondary beam was 2.6% pure and contained many contaminants most of which are located in period four of the periodic table. 67Cu was separated from the beam contaminants with an average recovery of 74 ± 4% and a radiochemical purity of \u3e99%. The purified 67Cu was then used to radiolabel NOTA conjugated Panitumumab antibodies and injected into HCT-116 tumor bearing mice via tail vein injection. A five day biodistribution profile was obtained and the tumor uptake of 67Cu-NOTA-Bz-NCS-Panitumumab was measured to be 12.5 ± 0.7 % ID/g

Cyclotron production of high–specific activity 55Co and in vivo evaluation of the stability of 55Co metal-chelate-peptide complexes

This work describes the production of high–specific activity 55 Co and the evaluation of the stability of 55 Co-metal-chelate-peptide complexes in vivo. 55 Co was produced via the 58 Ni(p,α) 55 Co reaction and purified using anion exchange chromatography with an average recovery of 92% and an average specific activity of 1.96 GBq/μmol. 55 Co-DO3A and 55 Co-NO2A peptide complexes were radiolabeled at 3.7 MBq/μg and injected into HCT-116 tumor xenografted mice. Positron emission tomography (PET) and biodistribution studies were performed at 24 and 48 hours postinjection and compared to those of 55 CoCl 2 . Both 55 Co-metal-chelate complexes demonstrated good in vivo stability by reducing the radiotracers’ uptake in the liver by sixfold at 24 hours with ˜ 1% ID/g and at 48 hours with ˜ 0.5% ID/g and reducing uptake in the heart by fourfold at 24 hours with ˜ 0.7% ID/g and sevenfold at 48 hours with ˜ 0.35% ID/g. These results support the use of 55 Co as a promising new radiotracer for PET imaging of cancer and other diseases

Feasibility of isotope harvesting at a projectile fragmentation facility: ⁶⁷Cu

The work presented here describes a proof-of-principle experiment for the chemical extraction of (67)Cu from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A (67)Cu beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 ± 3% and the radiochemical yield was ≥95%. These results show that extraction of radioisotopes from an aqueous projectile-fragment beam dump is a feasible method for obtaining radiochemically pure isotopes

Design And Construction Of A Water Target System For Harvesting Radioisotopes At The National Superconducting Cyclotron Laboratory

A liquid water target system for harvesting radioisotopes at the National Superconducting Cyclotron Laboratory (NSCL) was designed and constructed as the initial step in proof-of-principle experiments to harvest useful radioisotopes from the Facility for Rare Isotope Beams (FRIB). FRIB will be a new national user facility for nuclear science, to be completed in 2020, at which radioisotopes will be collected synergistically from the water in cooling-loops for the primary beam dump that cycle the water at flow rates in excess of hundreds of gallons per minute. As part of the development of radiochemical expertise required to harvest long-lived radioisotopes of interest in this environment, the water target system described here was constructed and successfully used to collect a test beam of relativistic Na-24 ions produced at the NSCL. Future studies will involve collecting interesting transition metal isotopes such as Cu-67 from less purified secondary projectile fragment beams. (C) 2014 Elsevier B.V. All rights reserved

Feasibility of Isotope Harvesting at a Projectile Fragmentation Facility: Cu-67

The work presented here describes a proof-of-principle experiment for the chemical extraction of Cu-67 from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A Cu-67 beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 +/- 3% and the radiochemical yield was \u3e= 95%. These results show that extraction of radioisotopes from an aqueous projectile-fragment beam dump is a feasible method for obtaining radiochemically pure isotopes

Harvesting Cu-67 from the Collection of a Secondary Beam Cocktail at the National Superconducting Cyclotron Laboratory

Isotope harvesting is a promising new method to obtain isotopes for which there is no reliable continuous supply at present. To determine the possibility of obtaining radiochemically pure radioisotopes from an aqueous beam dump at a heavy-ion fragmentation facility, preliminary experiments were performed to chemically extract a copper isotope from a large mixture of projectile fragmentation products in an aqueous medium. In this work a 93 MeV/u secondary beam cocktail was collected in an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL) located on the Michigan State University (MSU) campus. The beam cocktail consisted of similar to 2.9% Cu-67 in a large mixture of co-produced isotopes ranging in atomic number from similar to 19 to 34. The chemical extraction of 67Cu was achieved via a two-step process: primary extraction using a divalent metal chelation disk followed by anion-exchange chromatography. A significant fraction (74 +/- 4%) of the 67Cu collected in the aqueous beam stop was recovered with \u3e99% radiochemical purity. To illustrate the utility of this product, the purified 67Cu material was then used to radiolabel an anti-EGFR antibody, Panitumumab, and injected into mice bearing colon cancer xenografts. The tumor uptake at 5 days postinjection was found to be 12.5 +/- 0.7% which was in very good agreement with previously reported studies with this radiolabeled antibody. The present results demonstrate that harvesting isotopes from a heavy-ion fragmentation facility could be a promising new method for obtaining high-quality isotopes that are not currently available by traditional methods