Cyclotron production of (225)Ac from an electroplated (226)Ra target

PURPOSE: We demonstrate cyclotron production of high-quality (225)Ac using an electroplated (226)Ra target. METHODS: (226)Ra was extracted from legacy Ra sources using a chelating resin. Subsequent ion-exchange purification gave pure (226)Ra with a certain amount of carrier Ba. The radium target was prepared by electroplating. We successfully deposited about 37 MBq of (226)Ra on a target box. Maximum activation was achieved using 15.6 MeV protons on the target at 20 µA for 5 h. Two functional resins with various concentrations of nitric acid purified (225)Ac and recovered (226)Ra. Cooling the intermediate (225)Ac for 2–3 weeks decayed the major byproduct of (226)Ac and increased the radionuclidic purity of (225)Ac. Repeating the same separation protocol provided high-quality (225)Ac. RESULTS: We obtained (225)Ac at a yield of about 2.4 MBq at the end of bombardment (EOB), and the subsequent initial purification gave 1.7 MBq of (225)Ac with (226)Ac/(225)Ac ratio of < 3% at 4 days from EOB. Additional cooling time coupled with the separation procedure (secondary purification) effectively increased the (225)Ac (4n + 1 series) radionuclidic purity up to 99 + %. The recovered (225)Ac had a similar identification to commercially available (225)Ac originating from a (229)Th/(225)Ac generator. CONCLUSION: This procedure, which involves the (226)Ra(p,2n)(225)Ac reaction and the appropriate purification, has the potential to be a major alternative pathway for (225)Ac production because it can be performed in any facility with a compact cyclotron to address the increasing demand for (225)Ac. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00259-021-05460-7.