Patent Number: 
Section: claims

1. A method, comprising the steps of:positioning a metal target within a crucible, the crucible comprising an open top;releasably positioning the crucible within a holder;positioning the holder within a target assembly, the target assembly including multiple converter plates positioned in relation to the metal target such that gamma rays emitted from the converter plates impact the metal target;directing an electron beam at the multiple converter plates, the converter plates producing gamma rays in response to the electron beam; whereinthe metal target within the open topped crucible is irradiated with the gamma rays; andthereafter, removing the open topped crucible and the metal target positioned within the crucible from the holder and the target assembly. 2. The method of claim 1, further comprising preparing the metal target prior to the irradiating by melting a metal and pouring the melted metal into the crucible. 3. The method of claim 1, wherein the electron beam has an energy of at least 20 MeV and a power of at least 1 kW. 4. The method of claim 1, further comprising cooling the multiple converter plates and the metal target with a coolant fluid during the step of irradiating. 5. The method of claim 4, wherein the coolant fluid comprises water. 6. The method of claim 4, wherein the coolant water is provided in a turbulent flow. 7. The method of claim 1, wherein the metal target includes zinc-68. 8. The method of claim 7, wherein upon the irradiation, a portion of the zinc-68 is converted to copper-67, the method including continuing the step of directing the electron beam at the multiple converter plates until the conversion yields a copper-67 total activity of about 2 μCi/g target or greater. 9. The method of claim 7, wherein upon the irradiation, a portion of the zinc-68 is converted to copper-67, the method including continuing the step of directing the electron beam at the multiple converter plates until the conversion yields a copper-67 total activity of about 5 μCi/g target-kW-hr of beam energy of the electron beam or greater. 10. The method of claim 1, wherein each of the multiple converter plates has a thickness of between 0.75 mm to 3.0 mm. 11. The method of claim 1, wherein the multiple converter plates are separated from one another by a plate separation of between 1 mm and 4 mm. 12. The method of claim 1, wherein the multiple converter plates comprise tungsten. 13. The method of claim 10, wherein the multiple converter plates comprise tantalum-coated tungsten plates. 14. The method of claim 2, wherein the metal comprises zinc combined with zinc oxide and wherein upon the melting, the zinc oxide separates from the zinc, and wherein the separated zinc oxide is not added to the crucible. 15. The method of claim 14, wherein the melted zinc is poured into the crucible by use of a funnel, and the zinc oxide remains in the funnel upon the pouring. 16. The method of claim 1, wherein the holder is releasably positioned within the target assembly.