New production routes for medical isotopes ⁶⁴Cu and ⁶⁷Cu using accelerator neutrons

We have measured the activation cross sections producing ⁶⁴Cu and ⁶⁷Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14MeV neutrons. We estimated the production yields of ⁶⁴Cu and ⁶⁷Cu by fast neutrons from ^natC(d,n) with ⁴⁰MeV 5mA deuterons. We used the present result together with the evaluated cross section of Zn isotopes. The calculated ⁶⁴Cu yield is 1.8 TBq (175 g ⁶⁴Zn) for 12 h of irradiation; the yields of ⁶⁷Cu by ⁶⁷Zn(n,p) ⁶⁷Cu and ⁶⁸Zn(n,x)⁶⁷Cu were 249 GBq (184 g ⁶⁷Zn) and 287 GBq (186 g 68Zn) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce ⁶⁷Cu with very little radionuclide impurity via the ⁶⁸Zn(n,x)⁶⁷Cu reaction, and showed the ⁶⁴Zn(n,p)⁶⁴Cu reaction to be a promising route to produce 64Cu. Both 67Cu and 64Cu are noted to be produced using fast neutrons.