Observation of ⁹⁹Mo radioactivity produced in natural molybdenum irradiated with an electron beam from a linear industrial accelerator

The authors present the first observation of the production of 99 Mo using a direct electron beam obtained from an electron linear accelerator in the 10–20 MeV energy region. Three disks of natural molybdenum, with diameters of 20 mm and thicknesses of 0.12 mm, 0.33 mm, and 1.13 mm, respectively, were irradiated by an electron beam with the most probable energies of 12.6 MeV and 15.6 MeV. The highest observed activity in the experiment was equal to 646 ± 30 kBq, which is in good agreement with Geant4 simulations. Although 99 Mo production is significantly higher with gamma beams, the presented results contribute to the analysis of an interesting electrodisintegration process.