COMPUTATION STUDY OF RADIOISOTOPES GALLIUM-68 (68Ga) PRODUCTION USING LONG-LIVED & HIGH ACTIVITY METHODS

Abstract

Radioisotopes used for gamma-ray-based diagnostics have the main problem that imaging resolution quality.Gallium-68 is a positron (β⁺) emitting radioisotope that has better imaging resolution than gamma-based radioisotopes. Gallium-68 (⁶⁸Ga) can be produced by irradiating natural gallium or zinc-68 enriched as a target with protons in an accelerator facility. Indonesia has planned to build a cyclotron type accelerator that operates in 13 MeV proton energy and 50 µA proton beam who has initials named DECY-13. Before it was commissioned for radioisotopes production purpose that was must conduct a preliminary study to determine ⁶⁸Ga optimum irradiation time and properties, one of which was the monte carlo computation method using PHITS v3.24 software. Simulations were begun by irradiating proton with natural gallium target for 25 days with 2 days cooling and zinc-68 enriched for 120 minutes with cooling 10 minutes. The results at EOB of the long-lived process using the ^natGa target obtained total radioactivity of 189.42 MBq (5.12 mCi). The total radioactivity result of high activity process which used ⁶⁸Zn enriched as a target was 268.6 GBq (7.259 Ci). the radioactivity was compared with another accelerator, that the long-lived process was too small and uneconomical to done, but the high activity process was feasible to produce. The results of this research expected will be considered as a feasibility study for the 68Ga production process in Indonesia in the future.