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Introduction The cyclotron-based 100 Mo(p,2n) 99m Tc transformation has been proposed as a viable alternative to the reactor based 235 U(n,f) 99 Mo→ 99m Tc strategy for production of 99m Tc. Despite efforts to theoretically model the amount of ground-state 99g Tc present at end of bombardment for the (p,2n) reaction, experimental validation has yet to be performed. The co-production of 99g Tc may have important implications in both the subsequent radiopharmaceutical chemistry and patient dosimetry upon injection. Methods To determine the extent of 99g Tc co-production, we have experimentally measured the 100 Mo(p,x) 99 Mo, 99m Tc, and 99g Tc excitation functions in the 8–18 MeV range using a combination of natural abundance and 97.42% enriched 100 Mo foils along with γ-ray spectrometry and ICP-MS. Although the excitation functions for production of 99 Mo and 99m Tc have been presented previously in the literature, to the best of our knowledge, this work presents the first experimental evaluation of the 100 Mo(p,2n) 99g Tc excitation function. Results From the experimental cross-section measurements, the 99m Tc production yields and 99m Tc/ 99m+g Tc nuclei ratio were calculated for various thick target irradiation conditions. Results suggest that TBq quantities of 99m Tc can be achieved with a 99m Tc/ 99m+g Tc nuclei ratio that is on par with the current 99 Mo/ 99m Tc generator standard eluted at a 24-h frequency. Conclusion These findings suggest that the cyclotron production of 99m Tc may be a feasible alternative to the current reactor-based production strategy. |
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