Study of dissolved radon and optimization of ²¹¹ Rn/ ²¹¹ At generator

Abstract Alpha particle therapy is gaining attention as a cancer treatment. 211 At, an α-emitting nuclide with a 7.2-h half-life, is ideal for labeled compound production and body retention. However, an accelerator is required for the nuclide production, which limits its use. To address this issue, a 211 Rn- 211 At generator was developed. This generator system utilizes 211 Rn for transport, and 211 At is produced by its decay for on-site use. This study analyzed the dissolution of Rn in solution to investigate gas-phase recovery conditions of Rn in the generator system. The dissolution of a Bi target in a nitric-hydrochloric acid mixture and subsequent neutralization has been shown to enhance the Rn recovery efficiency. In this study, the gas-phase Rn recovery rate reached 88 %, while 50 % of available At has been recovered, and further improvement can be expected in the future.