Development of Target Holder for the First Experiment on an Alternative Route for ⁶⁴Cu Radioisotope Production by Secondary Neutron Irradiation of a ⁶⁴ZnO Target

The target holder, as part of the target system for cyclotron-based radioisotope production, plays a crucial role in successful radioisotope production. The target holder has to be designed and developed so that it will not deform or melt should a beam of energetic particles irradiate the target. In this work, we develop and test a target holder for ⁶⁴Cu radioisotope production. The thermal distribution and structural analysis are simulated using ANSYS software. Based on the ANSYS simulation results, a maximum temperature of 84°C occurred on the titanium foil, while the maximum temperature in the target holder body was 35.6°C when an 11-MeV proton beam with a beam current of 25 μA was bombarded on the target holder.

We successfully test the target holder, and for the first time, we experimentally produce a ⁶⁴Cu radioisotope by secondary neutron irradiation of the ⁶⁴ZnO target. Using 11-MeV protons with a proton beam current of 25 μA incident on a 1-mm Ti foil for 5 min, we were able to generate secondary neutrons, and then the secondary neutrons irradiated 1 g of the enriched ⁶⁴ZnO target. Copper-64 produced from the ⁶⁴Zn(n,p)⁶⁴Cu nuclear reaction was eventually detected using a portable gamma spectrometer, and its radioactivity was measured using a dose calibrator. For the first time, this experimental study confirmed that as much as 48.8 ± 6.2 MBq/μAh radioactivity of ⁶⁴Cu was produced with no observed radioactive impurities.