Production of high-purity medical radio isotope ⁶⁴Cu with accelerator-based neutrons generated with 9 and 12 MeV deuterons

We conducted a feasibility study for producing a high-purity medical radioisotope ⁶⁴Cu from natural zinc with accelerator-based neutrons. ⁶⁴Cu isotopes were produced via the ⁶⁴Zn(n,p) reaction. The accelerator-based neutrons were generated via the C(d,n) reaction using low-energy deuterons of 9 and 12 MeV on a 1-mm-thick carbon target. First, the production purity was estimated using the evaluated nuclear data library JENDL-4.0 and our previously measured thick target neutron yield. We found that even when natural zinc was used as the starting material, significantly high-purity ⁶⁴Cu could be obtained. Next, irradiation experiments for producing ⁶⁴Cu using natural zinc were conducted at Kyushu University Tandem Laboratory, with the amounts of ⁶⁴Cu isotopes and other gamma-emission nuclides measured by a high-purity germanium detector. As a result, high-purity ⁶⁴Cu isotopes of 1.11(49) × 10⁰ and 3.70 (17) × 10⁰ Bq/g/C were produced with incident deuteron energies of 9 and 12 MeV, respectively.