Measurements of the excitation functions of radon and astatine isotopes from 7 Li-induced reactions with 209 Bi for development of a 211 Rn– 211 At generator

We have measured excitation functions of 209 Bi( 7 Li, 5n) 211 Rn, 209 Bi( 7 Li, 6n) 210 Rn, and other reactions, with the aim of realizing a 211 Rn/ 211 At generator for cancer therapy. On the basis of a comparison with theoretical predictions, we found that nuclides of 210 At are produced via a break-up process rather than from the 209 Bi( 7 Li, p5n) 210 At reaction. The excitation functions obtained in this study provide the most favorable conditions for 211 Rn production in terms of available radioactivity and nuclide purity of the irradiated material.