On Cyclotron-Based Production of Gallium-68 Isotope: A Computational Benchmark for the Production Yield & Shielding Considerations

Abstract

Gallium-68 (68Ga) has played a relevant role for the novel studies in the nuclear medicine area. Its production has been made traditionally and initially using 68Ge/68Ga generators. These devices represent some flaws, namely, high costs, low activity per elution, and long-time waiting between elutions. In order to address these concerns, the cyclotron-based production of 68Ga has been recently investigated and has shown promising outcomes regarding the activity at the end of bombardment for both solid and liquid targets. Currently, the use of computational codes and theoretical calculations takes relevance when it comes to calculating relevant nuclear physics quantities such as the production yield and the ambient dose rate. These outcomes are important for having a proper understanding of all the reactions involved during an irradiation routine with protons on a target. In this work, we used important cad-based programs, Monte Carlo codes, and a deterministic calculator with the objective of making a full benchmark with a previous experimental research. We also calculated the shielding requirements for this kind of isotope production facility. The proposed shielding materials and their respective thickness showed to be sufficient to avoid high ambient dose rates outside the machine. For the production yield, we found out that a hybrid combination of Monte Carlo codes and subsequently a computation with a deterministic calculator gave us more precise results for the irradiation conditions considered here.