Photonuclear production of ²²⁵Ac from ²²⁶Ra targets

Herein we report proof of principal production of ²²⁵Ac via ²²⁶Ra(γ, n)²²⁵Ra →β-²²⁵Ac and subsequent chemical separation via extraction chromatography using BDGA and Ln resins. Irradiation of 0.35 µg ²²⁶Ra with 39 MeV bremsstrahlung end-point energy photons produced ²²⁵Ra and ²²⁴Ra at a rate of 754 and 2215 kBq/g ²²⁶Ra/mA/h, respectively. The production rate of ²²⁵Ac determined at its peak radioactivity was 335 kBq/g ²²⁶Ra/mA/h. Radiochemically pure ²²⁵Ac was isolated with a minimum separation factor of 125,000 for ²²⁵Ac:²²⁶Ra. These results are promising and lay the foundation for future studies to scale-up production for preclinical quantities of high purity ²²⁵Ac using the ²²⁶Ra(γ, n)²²⁵Ra →β-²²⁵Ac approach.