Speaker
Description
Zirconium-89, with a half-life of 3.3 days, is one of the most promising radioisotopes for nuclear imaging based on monoclonal antibodies (Immuno-PET). Immuno-PET studies require that the half-life of the diagnostic radioactive isotope coincide with the biological half-life of the carriers (monoclonal antibodies), which exceeds 24 hours and averages 2-6 days. Thus, the half-life of 89Zr ideally matches the half-life of antibodies, and the average positron energy of 395 keV allows for high-resolution PET images.
Currently, the production of Zr-89 is carried out mainly in reactions with protons and deuterons. Accelerators of these particles are complex and expensive to maintain. A promising method for obtaining zirconium-89 is the use of widespread and economic electron accelerators.
However, it is tough to obtain the required radionuclide from the 90Zr(γ, n)89Zr reaction. It is difficult to isolate the Zr-89 from an irradiated zirconium matrix. Therefore, we have carried out studies of reactions with the emission of alpha particles. We studied (γ, αn) and (γ, α)-reactions on natural molybdenum, molybdenum enriched in the 94Mo isotope, natural zirconium, and natural niobium.
The experimental weighted average yields of the reactions under study at the boundary energy of bremsstrahlung gamma quanta of 20 MeV are as follows:
90Zr(γ,αn)85Sr: 0.030 ± 0.015 mbn
96Zr(γ,αn)91Sr: 0.15 ± 0.05 mbn
93Nb(γ,αn)88Mo: 1.16 ± 0.12 mbn
93Nb(γ,αn)88Mo: 0.97 ± 0.10 mbn
94Mo(γ,αn)89Zr: 1.04 ± 0.09 mbn
100Mo(γ,αn)95Zr: 0.03 ± 0.01 mbn
99Mo(γ,α)88Zr: 0.081 ± 0.009 mbn
The obtained data are discussed.
The reported study was funded by RFBR according to the research project 20-315-90124.
