⁹⁹Mo production cycle based on muon nuclear-capture reaction with infinite ⁹⁹Tc resources

The paper proposes a novel ⁹⁹Mo production cycle based on a⁹⁹Tc (μ^-, ν) ⁹⁹Mo reaction (Measday, 2001; Petitjen et al., 1971; Backenstoss et al., 1971; Measday et al., 2007; Niikura et al., 2024; Yamaguchi et al., 2025; Mizuno et al., 2025), utilizing an infinite supply of ⁹⁹Tc (Product Catalog; Ando and Takano, 1999; Oigawa, 2014). ⁹⁹Mo is the parent nucleus for ^99mTc (The NUCLEIDE), a medical radioisotope used in imaging diagnostics with SPECT (Single Photon Emission Computed Tomography) (Radioisotopes in Medicine; National Academies of Sciences et al., 2016). The ⁹⁹Tc (μ^-, ν) ⁹⁹Mo reaction generates ⁹⁹Mo and stable Mo isotopes in the ⁹⁹Tc target material (Measday, 2001; Petitjen et al., 1971; Backenstoss et al., 1971; Measday et al., 2007; Niikura et al., 2024; Yamaguchi et al., 2025; Mizuno et al., 2025). The Mo ions (MoO₄^2-) are separated from the ⁹⁹Tc ions (⁹⁹TcO₄^-), resulting in a high specific activity of ⁹⁹Mo. The ⁹⁹Mo is then used to fill standard ^99mTc generators (Radioisotopes in Medicine; National Academies of Sciences et al., 2016; Design principles of the 99Mo). ⁹⁹Mo continuously decays through β^--emission into ⁹⁹Tc (The NUCLEIDE). The ⁹⁹Tc is a radioactive nucleus that is preserved at ⁹⁹Mo handling facilities. It is a fission product of uranium in spent nuclear fuel, typically comprising 0.1% of its weight (Ando and Takano, 1999; Oigawa, 2014). The ⁹⁹Tc keeps high isotopic purity and can be chemically extracted (Product Catalog). Two primary sources of ⁹⁹Tc provide abundant raw materials for the production of ⁹⁹Mo. The paper describes a new ⁹⁹Mo production cycle, the muon nuclear-capture reaction (Measday, 2001; Petitjen et al., 1971; Backenstoss et al., 1971; Measday et al., 2007; Niikura et al., 2024; Yamaguchi et al., 2025; Mizuno et al., 2025), the ⁹⁹Tc (μ^-, ν) ⁹⁹Mo reaction, the processes of the ⁹⁹Mo production and separation, online ⁹⁹Mo production, the availability of an infinite ⁹⁹Tc resource (Product Catalog; Ando and Takano, 1999; Oigawa, 2014), and the advantages of using muon nuclear-capture reactions for radioisotope production.