In some embodiments, a chemical separation stage is connected to the generator to remove unwanted isotopes or fragments generated by the irradiation process. Some of the isotopes may be radioactive and thus the chemical separation stage allows for the production of a pure Actinium-225 solution that does not contain other radioactive materials to ensure the dose delivered to the patient is optimized. One example of chemical separation is described in Apostolidis et al. Anal. Chem. 77 (2005) 6288. Commercial products such as the DOWEX resins from Dow Chemical are specifically designed to separate actinium in aqueous solution and may be utilized in a process as disclosed herein.

Additional shielding, such as a lead, concrete, or water barrier, may be placed around the generator to protect the users from neutrons and gamma rays.

Embodiments of the disclosure also provide a method of producing Actinium-225, comprising bombarding a neutron target with neutrons from a neutron source to produce a proton beam, wherein the neutron target comprises nickel, manganese, or iron; and bombarding a proton target with the proton beam, wherein the proton target comprises radium-226. Neutrons produced by a radioactive isotope or a neutron generator will hit the neutron target which is a metal such as nickel, manganese, or iron. The metal target generates high energy protons. The protons hit a target that contains radium (Ra) in any physical form. Actinium 225 is produced along with several other isotopes that can be filtered out by a chemical extraction stage to provide purified Ac-225. In some embodiments, a proton energy of the proton beam is 10 MeV or higher, e.g at least 11, 12, 13, 14, or 15 MeV.