The 13 MeV cyclotron target for a dual production of 89Zr and 32P

Abstract

The production of medical radioisotopes using conventional cyclotrons still faces challenges such as relatively high production costs and limited efficiency when each radionuclide is produced using separate targets. Using multi-material targets offers the chance to produce several radionuclides in a single irradiation process. However, designing an optimal target isn’t simple because the interaction between the secondary neutron field and the target geometry can affect the radionuclide yield. To address this problem, this study designed and optimized a 13 MeV cyclotron target system utilizing ^nat Y and ^natS for the simultaneous production of ⁸⁹Zr and ³²P. A combined approach of Particle and Heavy Ion Transport Code System (PHITS) simulations and Response Surface Methodology (RSM) was used to evaluate five geometrical factors systematically. These factors included the length ( L_Y ) and radius ( R_Y ) of yttrium, the forward ( L_S ) and backward ( B_S ) lengths, and the thickness ( T_S ) of sulfur. The RSM predicted that  ⁸⁹Zr and ³²P yields of 52.173 MBq/ m Ah and 0.014171 MBq/ m Ah, respectively, for the optimized configuration with: L_Y 0.0254 cm, R_Y 0.3000 cm, L_S 1.9124 cm, B_S 1.9124 cm, and T_S 1.9124 cm. Additional PHITS simulations using that configuration confirmed the RSM prediction of ⁸⁹Zr and ³²P yields, with deviations of 3.91% and 3.60%. These simulation results suggest that the proposed dual-target configuration can improve the production performance of the investigated radioisotopes and warrants further experimental investigation.