Cyclotron production of 211At/211gPo by 209Bi(alpha,2n) reaction

Astatine-211 (T1/2 = 7.214 h) is an α-emitter at secular equilibrium by EC with its ultra-short-lived α-emitting daughter, polonium-211g(T1/2 = 0.516 s), with a high Linear Energy Transfer (LET – 130 eV.nm–1) and a half-life suitable for metabolic radiotherapy; the overall α branching of the 211At/211gPo system is 100%. The direct production of 209Bi(α,2n)211At/211gPo seems the most satisfactory method; Bi targets were irradiated at JRC-Ispra Cyclotron of European Commission, EC, using α-energy higher than 28.61 MeV in order to produce, via 209Bi(α,3n)reaction, small amounts of the γ-emitter 210At (used as internal spike).