The process for producing Actinium-225 from RaCl₂ material depends mainly on the proton energy interacting with RaCl₂. FIG. 3 shows the dependence of producing Ac-225 on the proton energy. Even though 6 proton energies were simulated in the first stage, starting at 2.5 MeV, the figure only shows three curves because the probability of producing Ac-225 from protons with energies below or equal to 10 MeV is between 0.0006% and 0.0008%. The best RaCl₂ thickness to produce Ac-225 for 15 MeV and 20 MeV protons was determined to be 5 mm. To calculate the activity of the generated Actinium using the curves from FIG. 3, a 1 Ci proton source incident on a 5 mm thick RaCl₂ target will result in 32 uCi and 68 uCi for the 10 MeV and the 15 MeV proton energies respectively.