Radiative-capture studies of the giant dipole resonance. Gamma-ray yields from capture of protons and alpha-particles give finer details than studies of gamma-ray absorption

Feasibility of a novel photoproduction of 225Ac and 227Th with natural thorium target

We propose an innovative way to produce both ²²⁵Ac and ²²⁷Th, two precious radioisotopes enabling promising targeted alpha therapy, in a natural thorium target bombarded with a 30–90 MeV electron beam. Bremsstrahlung photons in the target are analyzed by MCNP and in-situ photonuclear transmutation of ²³²Th is evaluated by using the TENDL nuclear data. In the photo-transmutation analysis, 13 nuclides including ²²⁹Th and ²³¹Pa are modelled. Special procedures with chemical separations are also proposed to produce pure ²²⁵Ac and ²²⁷Th in separate streams. In addition, performance of the new approach is compared with conventional methods in terms of the ²²⁵Ac and ²²⁷Th yields. After a Th target is bombarded with a 500 kW electron beam for a year, yearly ²²⁵Ac yield is ~ 8.47 GBq (semi-permanently) and yearly ²²⁷Th yield is ~ 48.9 GBq over 50 years, and their yields are at least doubled in a 2-year irradiation. This work will help increase global supply of the two precious isotopes and would invariably help advance TAT-related researches and developments.