|Astatine isotopes may be obtained from bismuth exposed to alpha-radiation. When the bombardment energy is increased until 30 MeV the reaction with releasing 3 neutrons will yield astatine-210 instead of astatine-211. |
In another method of obtaining astatine is bombarding the golden target is bombarded by accelerated carbon nuclei, during which particularly the following reaction is going on:
,sup>19779Au + 126C -> 20585At + 410n
For extracting from bismuth or golden targets its halogen volatility is utilized. The distillation takes place in nitrogen or in vacuum as the target is heated until 300...600°C. Astatine is condensed on the glass wall of the trap cooled by liquid nitrogen or dry ice.
One more method is based on reaction of uranium or thorium nuclei decay under alpha-particles or high energy protons radiation.