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

Abstract

Abstract We propose an innovative way to produce both 225 Ac and 227 Th, 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 232 Th is evaluated by using the TENDL nuclear data. In the photo-transmutation analysis, 13 nuclides including 229 Th and 231 Pa are modelled. Special procedures with chemical separations are also proposed to produce pure 225 Ac and 227 Th in separate streams. In addition, performance of the new approach is compared with conventional methods in terms of the 225 Ac and 227 Th yields. After a Th target is bombarded with a 500 kW electron beam for a year, yearly 225 Ac yield is ~ 8.47 GBq (semi-permanently) and yearly 227 Th 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.

Topics & Concepts