Manufacturing and characterization of molybdenum pellets used as targets for 99m Tc production in cyclotron

Studies on electrochemical dissolution of sintered molybdenum discs as a potential method for targets dissolution in 99mTc production

“…Natural metal molybdenum powder (≥ 99.9% chemical purity) with a particle size of 1-2 µm in diameter used to prepare pressed and sintered discs was obtained from Sigma-Aldrich, Poland. Molybdenum discs with a density of 9.4 g/cm 3 , a diameter of 12 mm, and a thickness of 0.6 mm were manufactured by pressing molybdenum powder, followed by their sintering in hydrogen flow at a temperature of 1600 °C [31]. The mass of each molybdenum disc was 712 ± 10 mg (n = 15) and corresponded to the mass of 100 Mo target irradiated in cyclotron [34].…”

“…However, the appropriate technique must be employed to prepare it in a durable target resistant to a high current beam. The approaches to prepare natural and enriched molybdenum targets included the use of foils [30], pressed and sintered powder [15,16,31], physical vapor deposition (PVD) [32], and electrophoretic deposition [33]. In our previous work, we demonstrated the manufacturing of a high-density 100 Mo metallic target using pressing of molybdenum powder into pellets and their subsequent sintering in a reductive atmosphere [31].…”

“…The pressed and sintered molybdenum disc with a mass of 720 mg dissolved under these conditions within 60 and 45 min, respectively. A significantly longer time of dissolution of sintered molybdenum results from less porous structure and hence increasing hardness and mechanical strength after a high-temperature process carried out in a hydrogen atmosphere [31]. There are reported results of a higher dissolution rate of molybdenum sintered discs [35].…”

Potential Application of Ionic Liquids for Electrodeposition of the Material Targets for Production of Diagnostic Radioisotopes

“…Natural or enriched molybdenum targets are prepared by sintering elemental Mo powder, its melting or direct use of metallic molybdenum foil [98,99] and ref. therein.…”

“…In turn Krishna et al [137] used 1-butyl-3-methylimidazolium chloride ionic liquid with or without fission products (e.g., Pd, Ru) as a medium for examination of the spectroscopic and electrochemical behavior of UO 2 2+ ions. As it was aforementioned, as the targets for reactor production of 99 Mo, uranium coated with other elements or its alloys are considered. For instance, to improve the corrosion resistance of the material, Jiang et al [143] electrodeposition thin films of aluminum on uranium (U) substrate from (2AlCl 3 :1[EMIm]Cl) ionic liquid at room temperature.…”